diff --git a/compiler/rustc_ast_lowering/src/expr.rs b/compiler/rustc_ast_lowering/src/expr.rs
index 2be2fca87c3c5..c6f24c1a19b48 100644
--- a/compiler/rustc_ast_lowering/src/expr.rs
+++ b/compiler/rustc_ast_lowering/src/expr.rs
@@ -1771,8 +1771,14 @@ impl<'hir> LoweringContext<'_, 'hir> {
         let pat = self.lower_pat(pat);
         let for_span =
             self.mark_span_with_reason(DesugaringKind::ForLoop, self.lower_span(e.span), None);
-        let head_span = self.mark_span_with_reason(DesugaringKind::ForLoop, head.span, None);
-        let pat_span = self.mark_span_with_reason(DesugaringKind::ForLoop, pat.span, None);
+        let for_ctxt = for_span.ctxt();
+
+        // Try to point both the head and pat spans to their position in the for loop
+        // rather than inside a macro.
+        let head_span =
+            head.span.find_ancestor_in_same_ctxt(e.span).unwrap_or(head.span).with_ctxt(for_ctxt);
+        let pat_span =
+            pat.span.find_ancestor_in_same_ctxt(e.span).unwrap_or(pat.span).with_ctxt(for_ctxt);
 
         let loop_hir_id = self.lower_node_id(e.id);
         let label = self.lower_label(opt_label, e.id, loop_hir_id);
diff --git a/tests/coverage/async_block.cov-map b/tests/coverage/async_block.cov-map
index 07d4c0eb3cd60..08f5a7b5d79ee 100644
--- a/tests/coverage/async_block.cov-map
+++ b/tests/coverage/async_block.cov-map
@@ -1,5 +1,5 @@
 Function name: async_block::main
-Raw bytes (41): 0x[01, 01, 01, 05, 01, 07, 01, 07, 01, 00, 0a, 02, 01, 09, 00, 0a, 05, 00, 0e, 00, 13, 02, 01, 0d, 00, 13, 02, 07, 09, 00, 1b, 02, 00, 1c, 00, 22, 01, 02, 01, 00, 02]
+Raw bytes (41): 0x[01, 01, 01, 05, 01, 07, 01, 07, 01, 00, 0a, 02, 01, 09, 00, 0a, 01, 00, 0e, 00, 13, 02, 01, 0d, 00, 13, 02, 07, 09, 00, 1b, 02, 00, 1c, 00, 22, 01, 02, 01, 00, 02]
 Number of files: 1
 - file 0 => $DIR/async_block.rs
 Number of expressions: 1
@@ -8,7 +8,7 @@ Number of file 0 mappings: 7
 - Code(Counter(0)) at (prev + 7, 1) to (start + 0, 10)
 - Code(Expression(0, Sub)) at (prev + 1, 9) to (start + 0, 10)
     = (c1 - c0)
-- Code(Counter(1)) at (prev + 0, 14) to (start + 0, 19)
+- Code(Counter(0)) at (prev + 0, 14) to (start + 0, 19)
 - Code(Expression(0, Sub)) at (prev + 1, 13) to (start + 0, 19)
     = (c1 - c0)
 - Code(Expression(0, Sub)) at (prev + 7, 9) to (start + 0, 27)
@@ -16,7 +16,7 @@ Number of file 0 mappings: 7
 - Code(Expression(0, Sub)) at (prev + 0, 28) to (start + 0, 34)
     = (c1 - c0)
 - Code(Counter(0)) at (prev + 2, 1) to (start + 0, 2)
-Highest counter ID seen: c1
+Highest counter ID seen: c0
 
 Function name: async_block::main::{closure#0}
 Raw bytes (31): 0x[01, 01, 01, 01, 05, 05, 01, 09, 1c, 00, 1d, 01, 01, 10, 00, 17, 05, 00, 18, 02, 0e, 02, 02, 14, 02, 0e, 01, 03, 09, 00, 0a]
diff --git a/tests/coverage/async_block.coverage b/tests/coverage/async_block.coverage
index 4e00024aebd2e..29d90931fa8df 100644
--- a/tests/coverage/async_block.coverage
+++ b/tests/coverage/async_block.coverage
@@ -5,8 +5,8 @@
    LL|       |extern crate executor;
    LL|       |
    LL|      1|fn main() {
-   LL|     17|    for i in 0..16 {
-                      ^16
+   LL|     16|    for i in 0..16 {
+                           ^1
    LL|     16|        let future = async {
    LL|     16|            if i >= 12 {
    LL|      4|                println!("big");
diff --git a/tests/coverage/continue.cov-map b/tests/coverage/continue.cov-map
index 1a839f19a0f5b..05efd2707817a 100644
--- a/tests/coverage/continue.cov-map
+++ b/tests/coverage/continue.cov-map
@@ -1,5 +1,5 @@
 Function name: continue::main
-Raw bytes (241): 0x[01, 01, 1a, 05, 01, 05, 13, 01, 09, 05, 13, 01, 09, 0d, 01, 0d, 27, 01, 11, 0d, 27, 01, 11, 15, 01, 15, 33, 01, 19, 1d, 01, 1d, 47, 01, 21, 1d, 47, 01, 21, 25, 01, 25, 53, 01, 29, 25, 01, 2d, 01, 63, 2d, 01, 31, 2d, 01, 25, 01, 03, 01, 00, 0a, 01, 01, 09, 00, 10, 01, 00, 13, 00, 2e, 01, 02, 09, 00, 0e, 01, 00, 11, 00, 12, 05, 01, 0e, 00, 13, 02, 01, 0f, 00, 16, 09, 02, 11, 00, 19, 0e, 02, 12, 02, 0e, 0e, 04, 09, 00, 0e, 0d, 02, 0e, 00, 13, 16, 01, 0f, 00, 16, 22, 01, 16, 02, 0e, 11, 04, 11, 00, 19, 22, 03, 09, 00, 0e, 15, 02, 0e, 00, 13, 2a, 01, 0f, 00, 16, 19, 01, 15, 02, 0e, 2e, 04, 11, 00, 19, 19, 03, 09, 00, 0e, 1d, 02, 0e, 00, 13, 36, 01, 0c, 00, 13, 21, 01, 0d, 00, 15, 42, 01, 09, 00, 0a, 42, 01, 09, 00, 0e, 25, 02, 0e, 00, 13, 56, 01, 0f, 00, 16, 4e, 01, 16, 02, 0e, 29, 03, 12, 02, 0e, 56, 04, 09, 00, 0e, 2d, 02, 0e, 00, 13, 31, 01, 0f, 00, 16, 66, 01, 16, 02, 0e, 5e, 04, 11, 00, 16, 66, 03, 09, 00, 0e, 01, 02, 0d, 00, 0e, 01, 01, 01, 00, 02]
+Raw bytes (241): 0x[01, 01, 1a, 05, 01, 05, 13, 01, 09, 05, 13, 01, 09, 0d, 01, 0d, 27, 01, 11, 0d, 27, 01, 11, 15, 01, 15, 33, 01, 19, 1d, 01, 1d, 47, 01, 21, 1d, 47, 01, 21, 25, 01, 25, 53, 01, 29, 25, 01, 31, 01, 63, 31, 01, 2d, 31, 01, 25, 01, 03, 01, 00, 0a, 01, 01, 09, 00, 10, 01, 00, 13, 00, 2e, 01, 02, 09, 00, 0e, 01, 00, 11, 00, 12, 01, 01, 0e, 00, 13, 02, 01, 0f, 00, 16, 09, 02, 11, 00, 19, 0e, 02, 12, 02, 0e, 0e, 04, 09, 00, 0e, 01, 02, 0e, 00, 13, 16, 01, 0f, 00, 16, 22, 01, 16, 02, 0e, 11, 04, 11, 00, 19, 22, 03, 09, 00, 0e, 01, 02, 0e, 00, 13, 2a, 01, 0f, 00, 16, 19, 01, 15, 02, 0e, 2e, 04, 11, 00, 19, 19, 03, 09, 00, 0e, 01, 02, 0e, 00, 13, 36, 01, 0c, 00, 13, 21, 01, 0d, 00, 15, 42, 01, 09, 00, 0a, 42, 01, 09, 00, 0e, 01, 02, 0e, 00, 13, 56, 01, 0f, 00, 16, 4e, 01, 16, 02, 0e, 29, 03, 12, 02, 0e, 56, 04, 09, 00, 0e, 01, 02, 0e, 00, 13, 2d, 01, 0f, 00, 16, 66, 01, 16, 02, 0e, 5e, 04, 11, 00, 16, 66, 03, 09, 00, 0e, 01, 02, 0d, 00, 0e, 01, 01, 01, 00, 02]
 Number of files: 1
 - file 0 => $DIR/continue.rs
 Number of expressions: 26
@@ -25,17 +25,17 @@ Number of expressions: 26
 - expression 19 operands: lhs = Counter(9), rhs = Expression(20, Add)
 - expression 20 operands: lhs = Counter(0), rhs = Counter(10)
 - expression 21 operands: lhs = Counter(9), rhs = Counter(0)
-- expression 22 operands: lhs = Counter(11), rhs = Counter(0)
-- expression 23 operands: lhs = Expression(24, Add), rhs = Counter(11)
-- expression 24 operands: lhs = Counter(0), rhs = Counter(12)
-- expression 25 operands: lhs = Counter(11), rhs = Counter(0)
+- expression 22 operands: lhs = Counter(12), rhs = Counter(0)
+- expression 23 operands: lhs = Expression(24, Add), rhs = Counter(12)
+- expression 24 operands: lhs = Counter(0), rhs = Counter(11)
+- expression 25 operands: lhs = Counter(12), rhs = Counter(0)
 Number of file 0 mappings: 37
 - Code(Counter(0)) at (prev + 3, 1) to (start + 0, 10)
 - Code(Counter(0)) at (prev + 1, 9) to (start + 0, 16)
 - Code(Counter(0)) at (prev + 0, 19) to (start + 0, 46)
 - Code(Counter(0)) at (prev + 2, 9) to (start + 0, 14)
 - Code(Counter(0)) at (prev + 0, 17) to (start + 0, 18)
-- Code(Counter(1)) at (prev + 1, 14) to (start + 0, 19)
+- Code(Counter(0)) at (prev + 1, 14) to (start + 0, 19)
 - Code(Expression(0, Sub)) at (prev + 1, 15) to (start + 0, 22)
     = (c1 - c0)
 - Code(Counter(2)) at (prev + 2, 17) to (start + 0, 25)
@@ -43,7 +43,7 @@ Number of file 0 mappings: 37
     = (c1 - (c0 + c2))
 - Code(Expression(3, Sub)) at (prev + 4, 9) to (start + 0, 14)
     = (c1 - (c0 + c2))
-- Code(Counter(3)) at (prev + 2, 14) to (start + 0, 19)
+- Code(Counter(0)) at (prev + 2, 14) to (start + 0, 19)
 - Code(Expression(5, Sub)) at (prev + 1, 15) to (start + 0, 22)
     = (c3 - c0)
 - Code(Expression(8, Sub)) at (prev + 1, 22) to (start + 2, 14)
@@ -51,14 +51,14 @@ Number of file 0 mappings: 37
 - Code(Counter(4)) at (prev + 4, 17) to (start + 0, 25)
 - Code(Expression(8, Sub)) at (prev + 3, 9) to (start + 0, 14)
     = (c3 - (c0 + c4))
-- Code(Counter(5)) at (prev + 2, 14) to (start + 0, 19)
+- Code(Counter(0)) at (prev + 2, 14) to (start + 0, 19)
 - Code(Expression(10, Sub)) at (prev + 1, 15) to (start + 0, 22)
     = (c5 - c0)
 - Code(Counter(6)) at (prev + 1, 21) to (start + 2, 14)
 - Code(Expression(11, Sub)) at (prev + 4, 17) to (start + 0, 25)
     = (c5 - (c0 + c6))
 - Code(Counter(6)) at (prev + 3, 9) to (start + 0, 14)
-- Code(Counter(7)) at (prev + 2, 14) to (start + 0, 19)
+- Code(Counter(0)) at (prev + 2, 14) to (start + 0, 19)
 - Code(Expression(13, Sub)) at (prev + 1, 12) to (start + 0, 19)
     = (c7 - c0)
 - Code(Counter(8)) at (prev + 1, 13) to (start + 0, 21)
@@ -66,7 +66,7 @@ Number of file 0 mappings: 37
     = (c7 - (c0 + c8))
 - Code(Expression(16, Sub)) at (prev + 1, 9) to (start + 0, 14)
     = (c7 - (c0 + c8))
-- Code(Counter(9)) at (prev + 2, 14) to (start + 0, 19)
+- Code(Counter(0)) at (prev + 2, 14) to (start + 0, 19)
 - Code(Expression(21, Sub)) at (prev + 1, 15) to (start + 0, 22)
     = (c9 - c0)
 - Code(Expression(19, Sub)) at (prev + 1, 22) to (start + 2, 14)
@@ -74,15 +74,15 @@ Number of file 0 mappings: 37
 - Code(Counter(10)) at (prev + 3, 18) to (start + 2, 14)
 - Code(Expression(21, Sub)) at (prev + 4, 9) to (start + 0, 14)
     = (c9 - c0)
-- Code(Counter(11)) at (prev + 2, 14) to (start + 0, 19)
-- Code(Counter(12)) at (prev + 1, 15) to (start + 0, 22)
+- Code(Counter(0)) at (prev + 2, 14) to (start + 0, 19)
+- Code(Counter(11)) at (prev + 1, 15) to (start + 0, 22)
 - Code(Expression(25, Sub)) at (prev + 1, 22) to (start + 2, 14)
-    = (c11 - c0)
+    = (c12 - c0)
 - Code(Expression(23, Sub)) at (prev + 4, 17) to (start + 0, 22)
-    = ((c0 + c12) - c11)
+    = ((c0 + c11) - c12)
 - Code(Expression(25, Sub)) at (prev + 3, 9) to (start + 0, 14)
-    = (c11 - c0)
+    = (c12 - c0)
 - Code(Counter(0)) at (prev + 2, 13) to (start + 0, 14)
 - Code(Counter(0)) at (prev + 1, 1) to (start + 0, 2)
-Highest counter ID seen: c12
+Highest counter ID seen: c11
 
diff --git a/tests/coverage/continue.coverage b/tests/coverage/continue.coverage
index 17fe4874d151c..310701a1543cb 100644
--- a/tests/coverage/continue.coverage
+++ b/tests/coverage/continue.coverage
@@ -4,7 +4,7 @@
    LL|      1|    let is_true = std::env::args().len() == 1;
    LL|       |
    LL|      1|    let mut x = 0;
-   LL|     11|    for _ in 0..10 {
+   LL|      1|    for _ in 0..10 {
    LL|     10|        match is_true {
    LL|       |            true => {
    LL|     10|                continue;
@@ -15,7 +15,7 @@
    LL|       |        }
    LL|      0|        x = 3;
    LL|       |    }
-   LL|     11|    for _ in 0..10 {
+   LL|      1|    for _ in 0..10 {
    LL|     10|        match is_true {
    LL|      0|            false => {
    LL|      0|                x = 1;
@@ -26,7 +26,7 @@
    LL|       |        }
    LL|      0|        x = 3;
    LL|       |    }
-   LL|     11|    for _ in 0..10 {
+   LL|      1|    for _ in 0..10 {
    LL|     10|        match is_true {
    LL|     10|            true => {
    LL|     10|                x = 1;
@@ -37,13 +37,13 @@
    LL|       |        }
    LL|     10|        x = 3;
    LL|       |    }
-   LL|     11|    for _ in 0..10 {
+   LL|      1|    for _ in 0..10 {
    LL|     10|        if is_true {
    LL|     10|            continue;
    LL|      0|        }
    LL|      0|        x = 3;
    LL|       |    }
-   LL|     11|    for _ in 0..10 {
+   LL|      1|    for _ in 0..10 {
    LL|     10|        match is_true {
    LL|      0|            false => {
    LL|      0|                x = 1;
diff --git a/tests/coverage/inline.cov-map b/tests/coverage/inline.cov-map
index 4c67dd96ac2f5..55f4b8484c024 100644
--- a/tests/coverage/inline.cov-map
+++ b/tests/coverage/inline.cov-map
@@ -1,5 +1,5 @@
 Function name: inline::display::<char>
-Raw bytes (36): 0x[01, 01, 01, 05, 01, 06, 01, 29, 01, 00, 21, 02, 01, 09, 00, 0a, 05, 00, 0e, 00, 10, 02, 00, 11, 02, 06, 01, 03, 05, 00, 0d, 01, 01, 01, 00, 02]
+Raw bytes (36): 0x[01, 01, 01, 05, 01, 06, 01, 29, 01, 00, 21, 02, 01, 09, 00, 0a, 01, 00, 0e, 00, 10, 02, 00, 11, 02, 06, 01, 03, 05, 00, 0d, 01, 01, 01, 00, 02]
 Number of files: 1
 - file 0 => $DIR/inline.rs
 Number of expressions: 1
@@ -8,12 +8,12 @@ Number of file 0 mappings: 6
 - Code(Counter(0)) at (prev + 41, 1) to (start + 0, 33)
 - Code(Expression(0, Sub)) at (prev + 1, 9) to (start + 0, 10)
     = (c1 - c0)
-- Code(Counter(1)) at (prev + 0, 14) to (start + 0, 16)
+- Code(Counter(0)) at (prev + 0, 14) to (start + 0, 16)
 - Code(Expression(0, Sub)) at (prev + 0, 17) to (start + 2, 6)
     = (c1 - c0)
 - Code(Counter(0)) at (prev + 3, 5) to (start + 0, 13)
 - Code(Counter(0)) at (prev + 1, 1) to (start + 0, 2)
-Highest counter ID seen: c1
+Highest counter ID seen: c0
 
 Function name: inline::error
 Raw bytes (14): 0x[01, 01, 00, 02, 01, 31, 01, 00, 0b, 01, 01, 05, 00, 0b]
@@ -50,7 +50,7 @@ Number of file 0 mappings: 4
 Highest counter ID seen: c0
 
 Function name: inline::permutate::<char>
-Raw bytes (142): 0x[01, 01, 0e, 01, 05, 0d, 09, 0d, 09, 0d, 09, 0d, 09, 0d, 09, 0d, 09, 0d, 09, 0d, 09, 0d, 09, 0d, 09, 0d, 09, 01, 37, 05, 09, 16, 01, 0f, 01, 00, 38, 01, 01, 09, 00, 0a, 01, 00, 0d, 00, 13, 01, 00, 14, 00, 16, 01, 01, 08, 00, 0e, 05, 00, 0f, 02, 06, 02, 02, 0f, 00, 14, 2e, 01, 0d, 00, 0e, 09, 00, 12, 00, 13, 09, 00, 15, 00, 16, 2e, 00, 17, 04, 0a, 2e, 01, 0d, 00, 11, 2e, 00, 12, 00, 14, 2e, 00, 16, 00, 17, 2e, 00, 19, 00, 1a, 2e, 01, 0d, 00, 16, 2e, 00, 17, 00, 19, 2e, 00, 1b, 00, 20, 2e, 01, 0d, 00, 11, 2e, 00, 12, 00, 14, 32, 02, 0c, 02, 06, 01, 03, 01, 00, 02]
+Raw bytes (137): 0x[01, 01, 0e, 01, 05, 0d, 09, 0d, 09, 0d, 09, 0d, 09, 0d, 09, 0d, 09, 0d, 09, 0d, 09, 0d, 09, 0d, 09, 0d, 09, 01, 37, 05, 09, 15, 01, 0f, 01, 00, 38, 01, 01, 09, 00, 0a, 01, 00, 0d, 00, 13, 01, 00, 14, 00, 16, 01, 01, 08, 00, 0e, 05, 00, 0f, 02, 06, 02, 02, 0f, 00, 14, 2e, 01, 0d, 00, 0e, 09, 00, 12, 00, 16, 2e, 00, 17, 04, 0a, 2e, 01, 0d, 00, 11, 2e, 00, 12, 00, 14, 2e, 00, 16, 00, 17, 2e, 00, 19, 00, 1a, 2e, 01, 0d, 00, 16, 2e, 00, 17, 00, 19, 2e, 00, 1b, 00, 20, 2e, 01, 0d, 00, 11, 2e, 00, 12, 00, 14, 32, 02, 0c, 02, 06, 01, 03, 01, 00, 02]
 Number of files: 1
 - file 0 => $DIR/inline.rs
 Number of expressions: 14
@@ -68,7 +68,7 @@ Number of expressions: 14
 - expression 11 operands: lhs = Counter(3), rhs = Counter(2)
 - expression 12 operands: lhs = Counter(0), rhs = Expression(13, Add)
 - expression 13 operands: lhs = Counter(1), rhs = Counter(2)
-Number of file 0 mappings: 22
+Number of file 0 mappings: 21
 - Code(Counter(0)) at (prev + 15, 1) to (start + 0, 56)
 - Code(Counter(0)) at (prev + 1, 9) to (start + 0, 10)
 - Code(Counter(0)) at (prev + 0, 13) to (start + 0, 19)
@@ -79,8 +79,7 @@ Number of file 0 mappings: 22
     = (c0 - c1)
 - Code(Expression(11, Sub)) at (prev + 1, 13) to (start + 0, 14)
     = (c3 - c2)
-- Code(Counter(2)) at (prev + 0, 18) to (start + 0, 19)
-- Code(Counter(2)) at (prev + 0, 21) to (start + 0, 22)
+- Code(Counter(2)) at (prev + 0, 18) to (start + 0, 22)
 - Code(Expression(11, Sub)) at (prev + 0, 23) to (start + 4, 10)
     = (c3 - c2)
 - Code(Expression(11, Sub)) at (prev + 1, 13) to (start + 0, 17)
diff --git a/tests/coverage/inline.coverage b/tests/coverage/inline.coverage
index 5fe069d5389d8..190d5a3a22b1f 100644
--- a/tests/coverage/inline.coverage
+++ b/tests/coverage/inline.coverage
@@ -18,7 +18,7 @@
    LL|      6|        display(xs);
    LL|     10|    } else if k < n {
    LL|     15|        for i in k..n {
-                               ^10^10
+                               ^10
    LL|     15|            swap(xs, i, k);
    LL|     15|            permutate(xs, k + 1);
    LL|     15|            swap(xs, i, k);
@@ -40,8 +40,8 @@
    LL|     30|}
    LL|       |
    LL|      6|fn display<T: Display>(xs: &[T]) {
-   LL|     24|    for x in xs {
-                      ^18
+   LL|     18|    for x in xs {
+                           ^6
    LL|     18|        print!("{}", x);
    LL|     18|    }
    LL|      6|    println!();
diff --git a/tests/coverage/loops_branches.cov-map b/tests/coverage/loops_branches.cov-map
index 78fdaa53f46f1..96dd705044131 100644
--- a/tests/coverage/loops_branches.cov-map
+++ b/tests/coverage/loops_branches.cov-map
@@ -1,12 +1,13 @@
 Function name: <loops_branches::DebugTest as core::fmt::Debug>::fmt
-Raw bytes (137): 0x[01, 01, 04, 07, 0b, 01, 0d, 05, 09, 09, 0d, 19, 01, 09, 05, 00, 43, 01, 01, 0c, 00, 10, 01, 01, 10, 00, 15, 00, 01, 17, 00, 1b, 00, 00, 1c, 00, 1e, 01, 01, 0d, 00, 0e, 01, 01, 0d, 00, 13, 01, 00, 14, 00, 15, 01, 00, 17, 00, 1d, 05, 00, 1e, 00, 1f, 00, 01, 10, 01, 0a, 0d, 03, 0d, 00, 0e, 09, 00, 12, 00, 17, 0d, 01, 10, 00, 14, 0d, 01, 14, 00, 19, 00, 01, 1b, 00, 1f, 00, 00, 20, 00, 22, 0d, 01, 11, 00, 12, 0d, 01, 11, 00, 17, 0d, 00, 18, 00, 19, 0d, 00, 1b, 00, 21, 02, 00, 22, 00, 23, 00, 01, 14, 01, 0e, 0e, 03, 09, 00, 0f, 01, 01, 05, 00, 06]
+Raw bytes (139): 0x[01, 01, 05, 01, 05, 0b, 0f, 01, 09, 05, 0d, 0d, 09, 19, 01, 09, 05, 00, 43, 01, 01, 0c, 00, 10, 01, 01, 10, 00, 15, 00, 01, 17, 00, 1b, 00, 00, 1c, 00, 1e, 01, 01, 0d, 00, 0e, 01, 01, 0d, 00, 13, 01, 00, 14, 00, 15, 01, 00, 17, 00, 1d, 05, 00, 1e, 00, 1f, 00, 01, 10, 01, 0a, 09, 03, 0d, 00, 0e, 02, 00, 12, 00, 17, 09, 01, 10, 00, 14, 09, 01, 14, 00, 19, 00, 01, 1b, 00, 1f, 00, 00, 20, 00, 22, 09, 01, 11, 00, 12, 09, 01, 11, 00, 17, 09, 00, 18, 00, 19, 09, 00, 1b, 00, 21, 06, 00, 22, 00, 23, 00, 01, 14, 01, 0e, 12, 03, 09, 00, 0f, 01, 01, 05, 00, 06]
 Number of files: 1
 - file 0 => $DIR/loops_branches.rs
-Number of expressions: 4
-- expression 0 operands: lhs = Expression(1, Add), rhs = Expression(2, Add)
-- expression 1 operands: lhs = Counter(0), rhs = Counter(3)
-- expression 2 operands: lhs = Counter(1), rhs = Counter(2)
-- expression 3 operands: lhs = Counter(2), rhs = Counter(3)
+Number of expressions: 5
+- expression 0 operands: lhs = Counter(0), rhs = Counter(1)
+- expression 1 operands: lhs = Expression(2, Add), rhs = Expression(3, Add)
+- expression 2 operands: lhs = Counter(0), rhs = Counter(2)
+- expression 3 operands: lhs = Counter(1), rhs = Counter(3)
+- expression 4 operands: lhs = Counter(3), rhs = Counter(2)
 Number of file 0 mappings: 25
 - Code(Counter(0)) at (prev + 9, 5) to (start + 0, 67)
 - Code(Counter(0)) at (prev + 1, 12) to (start + 0, 16)
@@ -19,33 +20,35 @@ Number of file 0 mappings: 25
 - Code(Counter(0)) at (prev + 0, 23) to (start + 0, 29)
 - Code(Counter(1)) at (prev + 0, 30) to (start + 0, 31)
 - Code(Zero) at (prev + 1, 16) to (start + 1, 10)
-- Code(Counter(3)) at (prev + 3, 13) to (start + 0, 14)
-- Code(Counter(2)) at (prev + 0, 18) to (start + 0, 23)
-- Code(Counter(3)) at (prev + 1, 16) to (start + 0, 20)
-- Code(Counter(3)) at (prev + 1, 20) to (start + 0, 25)
+- Code(Counter(2)) at (prev + 3, 13) to (start + 0, 14)
+- Code(Expression(0, Sub)) at (prev + 0, 18) to (start + 0, 23)
+    = (c0 - c1)
+- Code(Counter(2)) at (prev + 1, 16) to (start + 0, 20)
+- Code(Counter(2)) at (prev + 1, 20) to (start + 0, 25)
 - Code(Zero) at (prev + 1, 27) to (start + 0, 31)
 - Code(Zero) at (prev + 0, 32) to (start + 0, 34)
-- Code(Counter(3)) at (prev + 1, 17) to (start + 0, 18)
-- Code(Counter(3)) at (prev + 1, 17) to (start + 0, 23)
-- Code(Counter(3)) at (prev + 0, 24) to (start + 0, 25)
-- Code(Counter(3)) at (prev + 0, 27) to (start + 0, 33)
-- Code(Expression(0, Sub)) at (prev + 0, 34) to (start + 0, 35)
-    = ((c0 + c3) - (c1 + c2))
+- Code(Counter(2)) at (prev + 1, 17) to (start + 0, 18)
+- Code(Counter(2)) at (prev + 1, 17) to (start + 0, 23)
+- Code(Counter(2)) at (prev + 0, 24) to (start + 0, 25)
+- Code(Counter(2)) at (prev + 0, 27) to (start + 0, 33)
+- Code(Expression(1, Sub)) at (prev + 0, 34) to (start + 0, 35)
+    = ((c0 + c2) - (c1 + c3))
 - Code(Zero) at (prev + 1, 20) to (start + 1, 14)
-- Code(Expression(3, Sub)) at (prev + 3, 9) to (start + 0, 15)
-    = (c2 - c3)
+- Code(Expression(4, Sub)) at (prev + 3, 9) to (start + 0, 15)
+    = (c3 - c2)
 - Code(Counter(0)) at (prev + 1, 5) to (start + 0, 6)
-Highest counter ID seen: c3
+Highest counter ID seen: c2
 
 Function name: <loops_branches::DisplayTest as core::fmt::Display>::fmt
-Raw bytes (137): 0x[01, 01, 04, 07, 0b, 01, 09, 05, 0d, 05, 09, 19, 01, 22, 05, 00, 43, 01, 01, 0c, 00, 11, 00, 00, 12, 01, 0a, 01, 02, 10, 00, 15, 00, 01, 17, 00, 1b, 00, 00, 1c, 00, 1e, 01, 01, 0d, 00, 0e, 01, 01, 0d, 00, 13, 01, 00, 14, 00, 15, 01, 00, 17, 00, 1d, 0d, 00, 1e, 00, 1f, 09, 02, 0d, 00, 0e, 05, 00, 12, 00, 17, 09, 01, 10, 00, 15, 00, 00, 16, 01, 0e, 09, 02, 14, 00, 19, 00, 01, 1b, 00, 1f, 00, 00, 20, 00, 22, 09, 01, 11, 00, 12, 09, 01, 11, 00, 17, 09, 00, 18, 00, 19, 09, 00, 1b, 00, 21, 02, 00, 22, 00, 23, 0e, 03, 09, 00, 0f, 01, 01, 05, 00, 06]
+Raw bytes (139): 0x[01, 01, 05, 01, 05, 0b, 0f, 01, 09, 0d, 05, 0d, 09, 19, 01, 22, 05, 00, 43, 01, 01, 0c, 00, 11, 00, 00, 12, 01, 0a, 01, 02, 10, 00, 15, 00, 01, 17, 00, 1b, 00, 00, 1c, 00, 1e, 01, 01, 0d, 00, 0e, 01, 01, 0d, 00, 13, 01, 00, 14, 00, 15, 01, 00, 17, 00, 1d, 05, 00, 1e, 00, 1f, 09, 02, 0d, 00, 0e, 02, 00, 12, 00, 17, 09, 01, 10, 00, 15, 00, 00, 16, 01, 0e, 09, 02, 14, 00, 19, 00, 01, 1b, 00, 1f, 00, 00, 20, 00, 22, 09, 01, 11, 00, 12, 09, 01, 11, 00, 17, 09, 00, 18, 00, 19, 09, 00, 1b, 00, 21, 06, 00, 22, 00, 23, 12, 03, 09, 00, 0f, 01, 01, 05, 00, 06]
 Number of files: 1
 - file 0 => $DIR/loops_branches.rs
-Number of expressions: 4
-- expression 0 operands: lhs = Expression(1, Add), rhs = Expression(2, Add)
-- expression 1 operands: lhs = Counter(0), rhs = Counter(2)
-- expression 2 operands: lhs = Counter(1), rhs = Counter(3)
-- expression 3 operands: lhs = Counter(1), rhs = Counter(2)
+Number of expressions: 5
+- expression 0 operands: lhs = Counter(0), rhs = Counter(1)
+- expression 1 operands: lhs = Expression(2, Add), rhs = Expression(3, Add)
+- expression 2 operands: lhs = Counter(0), rhs = Counter(2)
+- expression 3 operands: lhs = Counter(3), rhs = Counter(1)
+- expression 4 operands: lhs = Counter(3), rhs = Counter(2)
 Number of file 0 mappings: 25
 - Code(Counter(0)) at (prev + 34, 5) to (start + 0, 67)
 - Code(Counter(0)) at (prev + 1, 12) to (start + 0, 17)
@@ -57,9 +60,10 @@ Number of file 0 mappings: 25
 - Code(Counter(0)) at (prev + 1, 13) to (start + 0, 19)
 - Code(Counter(0)) at (prev + 0, 20) to (start + 0, 21)
 - Code(Counter(0)) at (prev + 0, 23) to (start + 0, 29)
-- Code(Counter(3)) at (prev + 0, 30) to (start + 0, 31)
+- Code(Counter(1)) at (prev + 0, 30) to (start + 0, 31)
 - Code(Counter(2)) at (prev + 2, 13) to (start + 0, 14)
-- Code(Counter(1)) at (prev + 0, 18) to (start + 0, 23)
+- Code(Expression(0, Sub)) at (prev + 0, 18) to (start + 0, 23)
+    = (c0 - c1)
 - Code(Counter(2)) at (prev + 1, 16) to (start + 0, 21)
 - Code(Zero) at (prev + 0, 22) to (start + 1, 14)
 - Code(Counter(2)) at (prev + 2, 20) to (start + 0, 25)
@@ -69,12 +73,12 @@ Number of file 0 mappings: 25
 - Code(Counter(2)) at (prev + 1, 17) to (start + 0, 23)
 - Code(Counter(2)) at (prev + 0, 24) to (start + 0, 25)
 - Code(Counter(2)) at (prev + 0, 27) to (start + 0, 33)
-- Code(Expression(0, Sub)) at (prev + 0, 34) to (start + 0, 35)
-    = ((c0 + c2) - (c1 + c3))
-- Code(Expression(3, Sub)) at (prev + 3, 9) to (start + 0, 15)
-    = (c1 - c2)
+- Code(Expression(1, Sub)) at (prev + 0, 34) to (start + 0, 35)
+    = ((c0 + c2) - (c3 + c1))
+- Code(Expression(4, Sub)) at (prev + 3, 9) to (start + 0, 15)
+    = (c3 - c2)
 - Code(Counter(0)) at (prev + 1, 5) to (start + 0, 6)
-Highest counter ID seen: c3
+Highest counter ID seen: c2
 
 Function name: loops_branches::main
 Raw bytes (54): 0x[01, 01, 00, 0a, 01, 37, 01, 00, 0a, 01, 01, 09, 00, 13, 01, 00, 16, 00, 1f, 01, 01, 05, 00, 0d, 01, 00, 0e, 00, 14, 01, 01, 09, 00, 15, 01, 00, 18, 00, 23, 01, 01, 05, 00, 0d, 01, 00, 0e, 00, 12, 01, 01, 01, 00, 02]
diff --git a/tests/coverage/loops_branches.coverage b/tests/coverage/loops_branches.coverage
index 8cd6f1be3f7a6..7bd1a680f00e3 100644
--- a/tests/coverage/loops_branches.coverage
+++ b/tests/coverage/loops_branches.coverage
@@ -16,8 +16,8 @@
    LL|      0|        } else {
    LL|      0|        }
    LL|       |
-   LL|     11|        for i in 0..10 {
-                          ^10
+   LL|     10|        for i in 0..10 {
+                               ^1
    LL|     10|            if true {
    LL|     10|                if false {
    LL|      0|                    while true {}
@@ -43,8 +43,8 @@
    LL|      1|            write!(f, "cool")?;
                                            ^0
    LL|       |        }
-   LL|     11|        for i in 0..10 {
-                          ^10
+   LL|     10|        for i in 0..10 {
+                               ^1
    LL|     10|            if false {
    LL|      0|            } else {
    LL|     10|                if false {
diff --git a/tests/coverage/nested_loops.cov-map b/tests/coverage/nested_loops.cov-map
index 649c65d8590ba..598068714b9a1 100644
--- a/tests/coverage/nested_loops.cov-map
+++ b/tests/coverage/nested_loops.cov-map
@@ -1,26 +1,26 @@
 Function name: nested_loops::main
-Raw bytes (164): 0x[01, 01, 14, 07, 47, 05, 11, 01, 0d, 47, 05, 01, 0d, 47, 05, 01, 0d, 47, 05, 01, 0d, 47, 05, 01, 0d, 3f, 05, 01, 09, 4b, 3f, 05, 15, 01, 09, 47, 4b, 01, 0d, 05, 15, 05, 01, 18, 01, 01, 01, 00, 0a, 01, 01, 09, 00, 10, 01, 00, 13, 00, 2e, 01, 01, 09, 00, 16, 01, 00, 19, 00, 1b, 05, 02, 13, 00, 20, 09, 01, 0d, 00, 12, 09, 00, 15, 00, 18, 09, 01, 0d, 00, 12, 09, 00, 15, 00, 18, 0d, 01, 12, 00, 17, 11, 01, 10, 00, 16, 02, 01, 11, 00, 16, 26, 01, 0d, 00, 0e, 26, 01, 0d, 00, 13, 26, 01, 0d, 00, 13, 26, 01, 10, 00, 16, 15, 01, 11, 00, 18, 15, 01, 14, 00, 1b, 2e, 01, 15, 00, 21, 36, 01, 18, 02, 12, 42, 03, 0d, 00, 0e, 4e, 02, 09, 00, 17, 01, 02, 01, 00, 02]
+Raw bytes (164): 0x[01, 01, 14, 07, 47, 05, 0d, 01, 11, 47, 05, 01, 11, 47, 05, 01, 11, 47, 05, 01, 11, 47, 05, 01, 11, 3f, 05, 01, 09, 4b, 3f, 05, 15, 01, 09, 47, 4b, 01, 11, 05, 15, 05, 01, 18, 01, 01, 01, 00, 0a, 01, 01, 09, 00, 10, 01, 00, 13, 00, 2e, 01, 01, 09, 00, 16, 01, 00, 19, 00, 1b, 05, 02, 13, 00, 20, 09, 01, 0d, 00, 12, 09, 00, 15, 00, 18, 09, 01, 0d, 00, 12, 09, 00, 15, 00, 18, 09, 01, 12, 00, 17, 0d, 01, 10, 00, 16, 02, 01, 11, 00, 16, 26, 01, 0d, 00, 0e, 26, 01, 0d, 00, 13, 26, 01, 0d, 00, 13, 26, 01, 10, 00, 16, 15, 01, 11, 00, 18, 15, 01, 14, 00, 1b, 2e, 01, 15, 00, 21, 36, 01, 18, 02, 12, 42, 03, 0d, 00, 0e, 4e, 02, 09, 00, 17, 01, 02, 01, 00, 02]
 Number of files: 1
 - file 0 => $DIR/nested_loops.rs
 Number of expressions: 20
 - expression 0 operands: lhs = Expression(1, Add), rhs = Expression(17, Add)
-- expression 1 operands: lhs = Counter(1), rhs = Counter(4)
-- expression 2 operands: lhs = Counter(0), rhs = Counter(3)
+- expression 1 operands: lhs = Counter(1), rhs = Counter(3)
+- expression 2 operands: lhs = Counter(0), rhs = Counter(4)
 - expression 3 operands: lhs = Expression(17, Add), rhs = Counter(1)
-- expression 4 operands: lhs = Counter(0), rhs = Counter(3)
+- expression 4 operands: lhs = Counter(0), rhs = Counter(4)
 - expression 5 operands: lhs = Expression(17, Add), rhs = Counter(1)
-- expression 6 operands: lhs = Counter(0), rhs = Counter(3)
+- expression 6 operands: lhs = Counter(0), rhs = Counter(4)
 - expression 7 operands: lhs = Expression(17, Add), rhs = Counter(1)
-- expression 8 operands: lhs = Counter(0), rhs = Counter(3)
+- expression 8 operands: lhs = Counter(0), rhs = Counter(4)
 - expression 9 operands: lhs = Expression(17, Add), rhs = Counter(1)
-- expression 10 operands: lhs = Counter(0), rhs = Counter(3)
+- expression 10 operands: lhs = Counter(0), rhs = Counter(4)
 - expression 11 operands: lhs = Expression(15, Add), rhs = Counter(1)
 - expression 12 operands: lhs = Counter(0), rhs = Counter(2)
 - expression 13 operands: lhs = Expression(18, Add), rhs = Expression(15, Add)
 - expression 14 operands: lhs = Counter(1), rhs = Counter(5)
 - expression 15 operands: lhs = Counter(0), rhs = Counter(2)
 - expression 16 operands: lhs = Expression(17, Add), rhs = Expression(18, Add)
-- expression 17 operands: lhs = Counter(0), rhs = Counter(3)
+- expression 17 operands: lhs = Counter(0), rhs = Counter(4)
 - expression 18 operands: lhs = Counter(1), rhs = Counter(5)
 - expression 19 operands: lhs = Counter(1), rhs = Counter(0)
 Number of file 0 mappings: 24
@@ -34,18 +34,18 @@ Number of file 0 mappings: 24
 - Code(Counter(2)) at (prev + 0, 21) to (start + 0, 24)
 - Code(Counter(2)) at (prev + 1, 13) to (start + 0, 18)
 - Code(Counter(2)) at (prev + 0, 21) to (start + 0, 24)
-- Code(Counter(3)) at (prev + 1, 18) to (start + 0, 23)
-- Code(Counter(4)) at (prev + 1, 16) to (start + 0, 22)
+- Code(Counter(2)) at (prev + 1, 18) to (start + 0, 23)
+- Code(Counter(3)) at (prev + 1, 16) to (start + 0, 22)
 - Code(Expression(0, Sub)) at (prev + 1, 17) to (start + 0, 22)
-    = ((c1 + c4) - (c0 + c3))
+    = ((c1 + c3) - (c0 + c4))
 - Code(Expression(9, Sub)) at (prev + 1, 13) to (start + 0, 14)
-    = ((c0 + c3) - c1)
+    = ((c0 + c4) - c1)
 - Code(Expression(9, Sub)) at (prev + 1, 13) to (start + 0, 19)
-    = ((c0 + c3) - c1)
+    = ((c0 + c4) - c1)
 - Code(Expression(9, Sub)) at (prev + 1, 13) to (start + 0, 19)
-    = ((c0 + c3) - c1)
+    = ((c0 + c4) - c1)
 - Code(Expression(9, Sub)) at (prev + 1, 16) to (start + 0, 22)
-    = ((c0 + c3) - c1)
+    = ((c0 + c4) - c1)
 - Code(Counter(5)) at (prev + 1, 17) to (start + 0, 24)
 - Code(Counter(5)) at (prev + 1, 20) to (start + 0, 27)
 - Code(Expression(11, Sub)) at (prev + 1, 21) to (start + 0, 33)
@@ -53,7 +53,7 @@ Number of file 0 mappings: 24
 - Code(Expression(13, Sub)) at (prev + 1, 24) to (start + 2, 18)
     = ((c1 + c5) - (c0 + c2))
 - Code(Expression(16, Sub)) at (prev + 3, 13) to (start + 0, 14)
-    = ((c0 + c3) - (c1 + c5))
+    = ((c0 + c4) - (c1 + c5))
 - Code(Expression(19, Sub)) at (prev + 2, 9) to (start + 0, 23)
     = (c1 - c0)
 - Code(Counter(0)) at (prev + 2, 1) to (start + 0, 2)
diff --git a/tests/coverage/nested_loops.coverage b/tests/coverage/nested_loops.coverage
index 143d0d26aa7f3..fbbec43309ed8 100644
--- a/tests/coverage/nested_loops.coverage
+++ b/tests/coverage/nested_loops.coverage
@@ -5,7 +5,7 @@
    LL|      1|    'outer: while countdown > 0 {
    LL|      1|        let mut a = 100;
    LL|      1|        let mut b = 100;
-   LL|      3|        for _ in 0..50 {
+   LL|      1|        for _ in 0..50 {
    LL|      3|            if a < 30 {
    LL|      0|                break;
    LL|      3|            }
diff --git a/tests/coverage/simple_match.cov-map b/tests/coverage/simple_match.cov-map
index cbd6c7ca52fd1..bc5a7e7b4bef4 100644
--- a/tests/coverage/simple_match.cov-map
+++ b/tests/coverage/simple_match.cov-map
@@ -1,5 +1,5 @@
 Function name: simple_match::main
-Raw bytes (99): 0x[01, 01, 05, 01, 05, 09, 01, 09, 01, 09, 13, 01, 0d, 11, 01, 04, 01, 00, 0a, 01, 04, 09, 00, 10, 01, 00, 13, 00, 2e, 01, 02, 09, 00, 16, 01, 00, 19, 00, 1a, 01, 01, 08, 00, 0f, 05, 00, 10, 02, 06, 02, 02, 05, 00, 06, 09, 05, 09, 00, 0d, 0a, 05, 0d, 00, 16, 0d, 02, 0d, 00, 0e, 0a, 02, 11, 02, 12, 0d, 04, 0d, 07, 0e, 0d, 01, 11, 00, 1e, 0d, 02, 15, 00, 16, 0e, 07, 0d, 00, 0f, 01, 03, 01, 00, 02]
+Raw bytes (99): 0x[01, 01, 05, 01, 05, 09, 01, 09, 01, 09, 13, 01, 0d, 11, 01, 04, 01, 00, 0a, 01, 04, 09, 00, 10, 01, 00, 13, 00, 2e, 01, 02, 09, 00, 16, 01, 00, 19, 00, 1a, 01, 01, 08, 00, 0f, 05, 00, 10, 02, 06, 02, 02, 05, 00, 06, 01, 05, 09, 00, 0d, 0a, 05, 0d, 00, 16, 0d, 02, 0d, 00, 0e, 0a, 02, 11, 02, 12, 0d, 04, 0d, 07, 0e, 0d, 01, 11, 00, 1e, 0d, 02, 15, 00, 16, 0e, 07, 0d, 00, 0f, 01, 03, 01, 00, 02]
 Number of files: 1
 - file 0 => $DIR/simple_match.rs
 Number of expressions: 5
@@ -18,7 +18,7 @@ Number of file 0 mappings: 17
 - Code(Counter(1)) at (prev + 0, 16) to (start + 2, 6)
 - Code(Expression(0, Sub)) at (prev + 2, 5) to (start + 0, 6)
     = (c0 - c1)
-- Code(Counter(2)) at (prev + 5, 9) to (start + 0, 13)
+- Code(Counter(0)) at (prev + 5, 9) to (start + 0, 13)
 - Code(Expression(2, Sub)) at (prev + 5, 13) to (start + 0, 22)
     = (c2 - c0)
 - Code(Counter(3)) at (prev + 2, 13) to (start + 0, 14)
diff --git a/tests/coverage/simple_match.coverage b/tests/coverage/simple_match.coverage
index 0ed7e8dc7887b..bd3f81aa8a1eb 100644
--- a/tests/coverage/simple_match.coverage
+++ b/tests/coverage/simple_match.coverage
@@ -16,7 +16,7 @@
    LL|       |    for
    LL|       |        _
    LL|       |    in
-   LL|      3|        0..2
+   LL|      1|        0..2
    LL|       |    {
    LL|       |        let z
    LL|       |        ;
diff --git a/tests/coverage/try_error_result.cov-map b/tests/coverage/try_error_result.cov-map
index e08f429615328..53757ef8a9bd6 100644
--- a/tests/coverage/try_error_result.cov-map
+++ b/tests/coverage/try_error_result.cov-map
@@ -62,77 +62,77 @@ Number of file 0 mappings: 8
 Highest counter ID seen: c1
 
 Function name: try_error_result::test1
-Raw bytes (82): 0x[01, 01, 04, 07, 05, 01, 09, 05, 01, 05, 09, 0e, 01, 0d, 01, 00, 1d, 01, 01, 09, 01, 12, 01, 01, 15, 00, 17, 05, 05, 09, 00, 0e, 09, 02, 09, 01, 11, 09, 04, 0d, 00, 1a, 02, 02, 0d, 00, 11, 02, 00, 29, 00, 2a, 00, 01, 0d, 00, 11, 00, 00, 2a, 00, 2b, 0a, 04, 0d, 00, 11, 00, 00, 2a, 00, 2b, 0e, 03, 05, 00, 0b, 01, 01, 01, 00, 02]
+Raw bytes (82): 0x[01, 01, 04, 07, 09, 01, 05, 09, 01, 09, 05, 0e, 01, 0d, 01, 00, 1d, 01, 01, 09, 01, 12, 01, 01, 15, 00, 17, 01, 05, 09, 00, 0e, 05, 02, 09, 01, 11, 05, 04, 0d, 00, 1a, 02, 02, 0d, 00, 11, 02, 00, 29, 00, 2a, 00, 01, 0d, 00, 11, 00, 00, 2a, 00, 2b, 0a, 04, 0d, 00, 11, 00, 00, 2a, 00, 2b, 0e, 03, 05, 00, 0b, 01, 01, 01, 00, 02]
 Number of files: 1
 - file 0 => $DIR/try_error_result.rs
 Number of expressions: 4
-- expression 0 operands: lhs = Expression(1, Add), rhs = Counter(1)
-- expression 1 operands: lhs = Counter(0), rhs = Counter(2)
-- expression 2 operands: lhs = Counter(1), rhs = Counter(0)
-- expression 3 operands: lhs = Counter(1), rhs = Counter(2)
+- expression 0 operands: lhs = Expression(1, Add), rhs = Counter(2)
+- expression 1 operands: lhs = Counter(0), rhs = Counter(1)
+- expression 2 operands: lhs = Counter(2), rhs = Counter(0)
+- expression 3 operands: lhs = Counter(2), rhs = Counter(1)
 Number of file 0 mappings: 14
 - Code(Counter(0)) at (prev + 13, 1) to (start + 0, 29)
 - Code(Counter(0)) at (prev + 1, 9) to (start + 1, 18)
 - Code(Counter(0)) at (prev + 1, 21) to (start + 0, 23)
-- Code(Counter(1)) at (prev + 5, 9) to (start + 0, 14)
-- Code(Counter(2)) at (prev + 2, 9) to (start + 1, 17)
-- Code(Counter(2)) at (prev + 4, 13) to (start + 0, 26)
+- Code(Counter(0)) at (prev + 5, 9) to (start + 0, 14)
+- Code(Counter(1)) at (prev + 2, 9) to (start + 1, 17)
+- Code(Counter(1)) at (prev + 4, 13) to (start + 0, 26)
 - Code(Expression(0, Sub)) at (prev + 2, 13) to (start + 0, 17)
-    = ((c0 + c2) - c1)
+    = ((c0 + c1) - c2)
 - Code(Expression(0, Sub)) at (prev + 0, 41) to (start + 0, 42)
-    = ((c0 + c2) - c1)
+    = ((c0 + c1) - c2)
 - Code(Zero) at (prev + 1, 13) to (start + 0, 17)
 - Code(Zero) at (prev + 0, 42) to (start + 0, 43)
 - Code(Expression(2, Sub)) at (prev + 4, 13) to (start + 0, 17)
-    = (c1 - c0)
+    = (c2 - c0)
 - Code(Zero) at (prev + 0, 42) to (start + 0, 43)
 - Code(Expression(3, Sub)) at (prev + 3, 5) to (start + 0, 11)
-    = (c1 - c2)
+    = (c2 - c1)
 - Code(Counter(0)) at (prev + 1, 1) to (start + 0, 2)
-Highest counter ID seen: c2
+Highest counter ID seen: c1
 
 Function name: try_error_result::test2
-Raw bytes (443): 0x[01, 01, 3d, 0d, 11, 0d, 57, 11, 15, 0d, 57, 11, 15, 0d, 57, 11, 15, 0d, 4f, 53, 1d, 57, 19, 11, 15, 0d, 57, 11, 15, 0d, 57, 11, 15, 0d, 53, 57, 19, 11, 15, 0d, 4f, 53, 1d, 57, 19, 11, 15, 41, 6b, 21, 25, 41, 21, 41, 6b, 21, 25, 09, 8f, 01, 93, 01, 2d, 0d, 29, 09, 0d, 09, 0d, 09, 93, 01, 0d, 29, 09, 8f, 01, 93, 01, 2d, 0d, 29, 45, a7, 01, 31, 35, 45, 31, 45, a7, 01, 31, 35, 49, bb, 01, 39, 3d, 49, 39, 49, bb, 01, 39, 3d, 05, 09, c7, 01, 09, cb, 01, 3d, cf, 01, 39, d3, 01, 35, d7, 01, 31, db, 01, 2d, df, 01, 29, e3, 01, 25, e7, 01, 21, eb, 01, 1d, ef, 01, 19, f3, 01, 15, 05, 11, 39, 01, 3d, 01, 00, 1d, 01, 01, 09, 00, 0f, 01, 00, 12, 00, 1a, 01, 01, 09, 01, 12, 01, 01, 15, 00, 17, 05, 05, 09, 00, 0e, 09, 02, 09, 01, 11, 09, 04, 0d, 00, 1a, 0d, 02, 0d, 00, 13, 0d, 00, 14, 00, 1f, 11, 00, 2f, 00, 30, 02, 00, 31, 00, 35, 02, 00, 45, 00, 4f, 02, 00, 50, 00, 62, 02, 01, 0d, 00, 13, 02, 02, 11, 00, 1c, 15, 01, 11, 00, 12, 36, 02, 11, 00, 15, 36, 02, 11, 00, 1b, 36, 01, 15, 00, 27, 4a, 02, 11, 00, 14, 36, 00, 17, 00, 1d, 36, 00, 1e, 00, 29, 19, 00, 41, 00, 42, 3e, 00, 43, 00, 47, 1d, 00, 5f, 00, 60, 4a, 01, 0d, 00, 17, 66, 01, 11, 00, 14, 41, 00, 17, 00, 1d, 41, 00, 1e, 00, 29, 21, 00, 41, 00, 42, 62, 00, 43, 00, 47, 25, 00, 60, 00, 61, 66, 01, 0d, 00, 17, 8a, 01, 04, 11, 00, 14, 7e, 00, 17, 00, 1d, 7e, 00, 1e, 00, 29, 29, 00, 42, 00, 43, 82, 01, 00, 44, 00, 48, 2d, 00, 61, 00, 62, 8a, 01, 01, 0d, 00, 17, a2, 01, 01, 11, 00, 14, 45, 00, 17, 00, 1d, 45, 01, 12, 00, 1d, 31, 00, 36, 00, 37, 9e, 01, 01, 12, 00, 16, 35, 00, 2f, 00, 30, a2, 01, 01, 0d, 00, 17, b6, 01, 01, 11, 00, 14, 49, 00, 17, 00, 1d, 49, 01, 12, 00, 1d, 39, 01, 11, 00, 12, b2, 01, 01, 12, 00, 16, 3d, 01, 11, 00, 12, b6, 01, 02, 0d, 00, 17, be, 01, 03, 05, 00, 0b, c2, 01, 01, 01, 00, 02]
+Raw bytes (443): 0x[01, 01, 3d, 09, 0d, 09, 57, 0d, 15, 09, 57, 0d, 15, 09, 57, 0d, 15, 09, 4f, 53, 1d, 57, 19, 0d, 15, 09, 57, 0d, 15, 09, 57, 0d, 15, 09, 53, 57, 19, 0d, 15, 09, 4f, 53, 1d, 57, 19, 0d, 15, 41, 6b, 21, 25, 41, 21, 41, 6b, 21, 25, 05, 8f, 01, 93, 01, 2d, 09, 29, 05, 09, 05, 09, 05, 93, 01, 09, 29, 05, 8f, 01, 93, 01, 2d, 09, 29, 45, a7, 01, 31, 35, 45, 31, 45, a7, 01, 31, 35, 49, bb, 01, 39, 3d, 49, 39, 49, bb, 01, 39, 3d, 11, 05, c7, 01, 05, cb, 01, 3d, cf, 01, 39, d3, 01, 35, d7, 01, 31, db, 01, 2d, df, 01, 29, e3, 01, 25, e7, 01, 21, eb, 01, 1d, ef, 01, 19, f3, 01, 15, 11, 0d, 39, 01, 3d, 01, 00, 1d, 01, 01, 09, 00, 0f, 01, 00, 12, 00, 1a, 01, 01, 09, 01, 12, 01, 01, 15, 00, 17, 01, 05, 09, 00, 0e, 05, 02, 09, 01, 11, 05, 04, 0d, 00, 1a, 09, 02, 0d, 00, 13, 09, 00, 14, 00, 1f, 0d, 00, 2f, 00, 30, 02, 00, 31, 00, 35, 02, 00, 45, 00, 4f, 02, 00, 50, 00, 62, 02, 01, 0d, 00, 13, 02, 02, 11, 00, 1c, 15, 01, 11, 00, 12, 36, 02, 11, 00, 15, 36, 02, 11, 00, 1b, 36, 01, 15, 00, 27, 4a, 02, 11, 00, 14, 36, 00, 17, 00, 1d, 36, 00, 1e, 00, 29, 19, 00, 41, 00, 42, 3e, 00, 43, 00, 47, 1d, 00, 5f, 00, 60, 4a, 01, 0d, 00, 17, 66, 01, 11, 00, 14, 41, 00, 17, 00, 1d, 41, 00, 1e, 00, 29, 21, 00, 41, 00, 42, 62, 00, 43, 00, 47, 25, 00, 60, 00, 61, 66, 01, 0d, 00, 17, 8a, 01, 04, 11, 00, 14, 7e, 00, 17, 00, 1d, 7e, 00, 1e, 00, 29, 29, 00, 42, 00, 43, 82, 01, 00, 44, 00, 48, 2d, 00, 61, 00, 62, 8a, 01, 01, 0d, 00, 17, a2, 01, 01, 11, 00, 14, 45, 00, 17, 00, 1d, 45, 01, 12, 00, 1d, 31, 00, 36, 00, 37, 9e, 01, 01, 12, 00, 16, 35, 00, 2f, 00, 30, a2, 01, 01, 0d, 00, 17, b6, 01, 01, 11, 00, 14, 49, 00, 17, 00, 1d, 49, 01, 12, 00, 1d, 39, 01, 11, 00, 12, b2, 01, 01, 12, 00, 16, 3d, 01, 11, 00, 12, b6, 01, 02, 0d, 00, 17, be, 01, 03, 05, 00, 0b, c2, 01, 01, 01, 00, 02]
 Number of files: 1
 - file 0 => $DIR/try_error_result.rs
 Number of expressions: 61
-- expression 0 operands: lhs = Counter(3), rhs = Counter(4)
-- expression 1 operands: lhs = Counter(3), rhs = Expression(21, Add)
-- expression 2 operands: lhs = Counter(4), rhs = Counter(5)
-- expression 3 operands: lhs = Counter(3), rhs = Expression(21, Add)
-- expression 4 operands: lhs = Counter(4), rhs = Counter(5)
-- expression 5 operands: lhs = Counter(3), rhs = Expression(21, Add)
-- expression 6 operands: lhs = Counter(4), rhs = Counter(5)
-- expression 7 operands: lhs = Counter(3), rhs = Expression(19, Add)
+- expression 0 operands: lhs = Counter(2), rhs = Counter(3)
+- expression 1 operands: lhs = Counter(2), rhs = Expression(21, Add)
+- expression 2 operands: lhs = Counter(3), rhs = Counter(5)
+- expression 3 operands: lhs = Counter(2), rhs = Expression(21, Add)
+- expression 4 operands: lhs = Counter(3), rhs = Counter(5)
+- expression 5 operands: lhs = Counter(2), rhs = Expression(21, Add)
+- expression 6 operands: lhs = Counter(3), rhs = Counter(5)
+- expression 7 operands: lhs = Counter(2), rhs = Expression(19, Add)
 - expression 8 operands: lhs = Expression(20, Add), rhs = Counter(7)
 - expression 9 operands: lhs = Expression(21, Add), rhs = Counter(6)
-- expression 10 operands: lhs = Counter(4), rhs = Counter(5)
-- expression 11 operands: lhs = Counter(3), rhs = Expression(21, Add)
-- expression 12 operands: lhs = Counter(4), rhs = Counter(5)
-- expression 13 operands: lhs = Counter(3), rhs = Expression(21, Add)
-- expression 14 operands: lhs = Counter(4), rhs = Counter(5)
-- expression 15 operands: lhs = Counter(3), rhs = Expression(20, Add)
+- expression 10 operands: lhs = Counter(3), rhs = Counter(5)
+- expression 11 operands: lhs = Counter(2), rhs = Expression(21, Add)
+- expression 12 operands: lhs = Counter(3), rhs = Counter(5)
+- expression 13 operands: lhs = Counter(2), rhs = Expression(21, Add)
+- expression 14 operands: lhs = Counter(3), rhs = Counter(5)
+- expression 15 operands: lhs = Counter(2), rhs = Expression(20, Add)
 - expression 16 operands: lhs = Expression(21, Add), rhs = Counter(6)
-- expression 17 operands: lhs = Counter(4), rhs = Counter(5)
-- expression 18 operands: lhs = Counter(3), rhs = Expression(19, Add)
+- expression 17 operands: lhs = Counter(3), rhs = Counter(5)
+- expression 18 operands: lhs = Counter(2), rhs = Expression(19, Add)
 - expression 19 operands: lhs = Expression(20, Add), rhs = Counter(7)
 - expression 20 operands: lhs = Expression(21, Add), rhs = Counter(6)
-- expression 21 operands: lhs = Counter(4), rhs = Counter(5)
+- expression 21 operands: lhs = Counter(3), rhs = Counter(5)
 - expression 22 operands: lhs = Counter(16), rhs = Expression(26, Add)
 - expression 23 operands: lhs = Counter(8), rhs = Counter(9)
 - expression 24 operands: lhs = Counter(16), rhs = Counter(8)
 - expression 25 operands: lhs = Counter(16), rhs = Expression(26, Add)
 - expression 26 operands: lhs = Counter(8), rhs = Counter(9)
-- expression 27 operands: lhs = Counter(2), rhs = Expression(35, Add)
+- expression 27 operands: lhs = Counter(1), rhs = Expression(35, Add)
 - expression 28 operands: lhs = Expression(36, Add), rhs = Counter(11)
-- expression 29 operands: lhs = Counter(3), rhs = Counter(10)
-- expression 30 operands: lhs = Counter(2), rhs = Counter(3)
-- expression 31 operands: lhs = Counter(2), rhs = Counter(3)
-- expression 32 operands: lhs = Counter(2), rhs = Expression(36, Add)
-- expression 33 operands: lhs = Counter(3), rhs = Counter(10)
-- expression 34 operands: lhs = Counter(2), rhs = Expression(35, Add)
+- expression 29 operands: lhs = Counter(2), rhs = Counter(10)
+- expression 30 operands: lhs = Counter(1), rhs = Counter(2)
+- expression 31 operands: lhs = Counter(1), rhs = Counter(2)
+- expression 32 operands: lhs = Counter(1), rhs = Expression(36, Add)
+- expression 33 operands: lhs = Counter(2), rhs = Counter(10)
+- expression 34 operands: lhs = Counter(1), rhs = Expression(35, Add)
 - expression 35 operands: lhs = Expression(36, Add), rhs = Counter(11)
-- expression 36 operands: lhs = Counter(3), rhs = Counter(10)
+- expression 36 operands: lhs = Counter(2), rhs = Counter(10)
 - expression 37 operands: lhs = Counter(17), rhs = Expression(41, Add)
 - expression 38 operands: lhs = Counter(12), rhs = Counter(13)
 - expression 39 operands: lhs = Counter(17), rhs = Counter(12)
@@ -143,8 +143,8 @@ Number of expressions: 61
 - expression 44 operands: lhs = Counter(18), rhs = Counter(14)
 - expression 45 operands: lhs = Counter(18), rhs = Expression(46, Add)
 - expression 46 operands: lhs = Counter(14), rhs = Counter(15)
-- expression 47 operands: lhs = Counter(1), rhs = Counter(2)
-- expression 48 operands: lhs = Expression(49, Add), rhs = Counter(2)
+- expression 47 operands: lhs = Counter(4), rhs = Counter(1)
+- expression 48 operands: lhs = Expression(49, Add), rhs = Counter(1)
 - expression 49 operands: lhs = Expression(50, Add), rhs = Counter(15)
 - expression 50 operands: lhs = Expression(51, Add), rhs = Counter(14)
 - expression 51 operands: lhs = Expression(52, Add), rhs = Counter(13)
@@ -156,48 +156,48 @@ Number of expressions: 61
 - expression 57 operands: lhs = Expression(58, Add), rhs = Counter(7)
 - expression 58 operands: lhs = Expression(59, Add), rhs = Counter(6)
 - expression 59 operands: lhs = Expression(60, Add), rhs = Counter(5)
-- expression 60 operands: lhs = Counter(1), rhs = Counter(4)
+- expression 60 operands: lhs = Counter(4), rhs = Counter(3)
 Number of file 0 mappings: 57
 - Code(Counter(0)) at (prev + 61, 1) to (start + 0, 29)
 - Code(Counter(0)) at (prev + 1, 9) to (start + 0, 15)
 - Code(Counter(0)) at (prev + 0, 18) to (start + 0, 26)
 - Code(Counter(0)) at (prev + 1, 9) to (start + 1, 18)
 - Code(Counter(0)) at (prev + 1, 21) to (start + 0, 23)
-- Code(Counter(1)) at (prev + 5, 9) to (start + 0, 14)
-- Code(Counter(2)) at (prev + 2, 9) to (start + 1, 17)
-- Code(Counter(2)) at (prev + 4, 13) to (start + 0, 26)
-- Code(Counter(3)) at (prev + 2, 13) to (start + 0, 19)
-- Code(Counter(3)) at (prev + 0, 20) to (start + 0, 31)
-- Code(Counter(4)) at (prev + 0, 47) to (start + 0, 48)
+- Code(Counter(0)) at (prev + 5, 9) to (start + 0, 14)
+- Code(Counter(1)) at (prev + 2, 9) to (start + 1, 17)
+- Code(Counter(1)) at (prev + 4, 13) to (start + 0, 26)
+- Code(Counter(2)) at (prev + 2, 13) to (start + 0, 19)
+- Code(Counter(2)) at (prev + 0, 20) to (start + 0, 31)
+- Code(Counter(3)) at (prev + 0, 47) to (start + 0, 48)
 - Code(Expression(0, Sub)) at (prev + 0, 49) to (start + 0, 53)
-    = (c3 - c4)
+    = (c2 - c3)
 - Code(Expression(0, Sub)) at (prev + 0, 69) to (start + 0, 79)
-    = (c3 - c4)
+    = (c2 - c3)
 - Code(Expression(0, Sub)) at (prev + 0, 80) to (start + 0, 98)
-    = (c3 - c4)
+    = (c2 - c3)
 - Code(Expression(0, Sub)) at (prev + 1, 13) to (start + 0, 19)
-    = (c3 - c4)
+    = (c2 - c3)
 - Code(Expression(0, Sub)) at (prev + 2, 17) to (start + 0, 28)
-    = (c3 - c4)
+    = (c2 - c3)
 - Code(Counter(5)) at (prev + 1, 17) to (start + 0, 18)
 - Code(Expression(13, Sub)) at (prev + 2, 17) to (start + 0, 21)
-    = (c3 - (c4 + c5))
+    = (c2 - (c3 + c5))
 - Code(Expression(13, Sub)) at (prev + 2, 17) to (start + 0, 27)
-    = (c3 - (c4 + c5))
+    = (c2 - (c3 + c5))
 - Code(Expression(13, Sub)) at (prev + 1, 21) to (start + 0, 39)
-    = (c3 - (c4 + c5))
+    = (c2 - (c3 + c5))
 - Code(Expression(18, Sub)) at (prev + 2, 17) to (start + 0, 20)
-    = (c3 - (((c4 + c5) + c6) + c7))
+    = (c2 - (((c3 + c5) + c6) + c7))
 - Code(Expression(13, Sub)) at (prev + 0, 23) to (start + 0, 29)
-    = (c3 - (c4 + c5))
+    = (c2 - (c3 + c5))
 - Code(Expression(13, Sub)) at (prev + 0, 30) to (start + 0, 41)
-    = (c3 - (c4 + c5))
+    = (c2 - (c3 + c5))
 - Code(Counter(6)) at (prev + 0, 65) to (start + 0, 66)
 - Code(Expression(15, Sub)) at (prev + 0, 67) to (start + 0, 71)
-    = (c3 - ((c4 + c5) + c6))
+    = (c2 - ((c3 + c5) + c6))
 - Code(Counter(7)) at (prev + 0, 95) to (start + 0, 96)
 - Code(Expression(18, Sub)) at (prev + 1, 13) to (start + 0, 23)
-    = (c3 - (((c4 + c5) + c6) + c7))
+    = (c2 - (((c3 + c5) + c6) + c7))
 - Code(Expression(25, Sub)) at (prev + 1, 17) to (start + 0, 20)
     = (c16 - (c8 + c9))
 - Code(Counter(16)) at (prev + 0, 23) to (start + 0, 29)
@@ -209,17 +209,17 @@ Number of file 0 mappings: 57
 - Code(Expression(25, Sub)) at (prev + 1, 13) to (start + 0, 23)
     = (c16 - (c8 + c9))
 - Code(Expression(34, Sub)) at (prev + 4, 17) to (start + 0, 20)
-    = (c2 - ((c3 + c10) + c11))
+    = (c1 - ((c2 + c10) + c11))
 - Code(Expression(31, Sub)) at (prev + 0, 23) to (start + 0, 29)
-    = (c2 - c3)
+    = (c1 - c2)
 - Code(Expression(31, Sub)) at (prev + 0, 30) to (start + 0, 41)
-    = (c2 - c3)
+    = (c1 - c2)
 - Code(Counter(10)) at (prev + 0, 66) to (start + 0, 67)
 - Code(Expression(32, Sub)) at (prev + 0, 68) to (start + 0, 72)
-    = (c2 - (c3 + c10))
+    = (c1 - (c2 + c10))
 - Code(Counter(11)) at (prev + 0, 97) to (start + 0, 98)
 - Code(Expression(34, Sub)) at (prev + 1, 13) to (start + 0, 23)
-    = (c2 - ((c3 + c10) + c11))
+    = (c1 - ((c2 + c10) + c11))
 - Code(Expression(40, Sub)) at (prev + 1, 17) to (start + 0, 20)
     = (c17 - (c12 + c13))
 - Code(Counter(17)) at (prev + 0, 23) to (start + 0, 29)
@@ -241,8 +241,8 @@ Number of file 0 mappings: 57
 - Code(Expression(45, Sub)) at (prev + 2, 13) to (start + 0, 23)
     = (c18 - (c14 + c15))
 - Code(Expression(47, Sub)) at (prev + 3, 5) to (start + 0, 11)
-    = (c1 - c2)
+    = (c4 - c1)
 - Code(Expression(48, Sub)) at (prev + 1, 1) to (start + 0, 2)
-    = (((((((((((((c1 + c4) + c5) + c6) + c7) + c8) + c9) + c10) + c11) + c12) + c13) + c14) + c15) - c2)
+    = (((((((((((((c4 + c3) + c5) + c6) + c7) + c8) + c9) + c10) + c11) + c12) + c13) + c14) + c15) - c1)
 Highest counter ID seen: c18
 
diff --git a/tests/coverage/try_error_result.coverage b/tests/coverage/try_error_result.coverage
index f2ec82f20fa2c..193c92cad48fe 100644
--- a/tests/coverage/try_error_result.coverage
+++ b/tests/coverage/try_error_result.coverage
@@ -17,7 +17,7 @@
    LL|       |    for
    LL|       |        _
    LL|       |    in
-   LL|      6|        0..10
+   LL|      1|        0..10
    LL|       |    {
    LL|      6|        countdown
    LL|      6|            -= 1
@@ -67,7 +67,7 @@
    LL|       |    for
    LL|       |        _
    LL|       |    in
-   LL|      6|        0..10
+   LL|      1|        0..10
    LL|       |    {
    LL|      6|        countdown
    LL|      6|            -= 1
diff --git a/tests/coverage/unicode.cov-map b/tests/coverage/unicode.cov-map
index bbfa8b940c6d7..b118c847e8fff 100644
--- a/tests/coverage/unicode.cov-map
+++ b/tests/coverage/unicode.cov-map
@@ -1,5 +1,5 @@
 Function name: unicode::main
-Raw bytes (58): 0x[01, 01, 02, 05, 01, 01, 0d, 0a, 01, 0e, 01, 00, 0a, 02, 01, 09, 00, 0c, 05, 00, 10, 00, 1b, 02, 00, 1c, 00, 28, 01, 02, 08, 00, 23, 09, 00, 29, 00, 44, 0d, 00, 47, 02, 06, 06, 02, 05, 00, 06, 01, 02, 05, 00, 0b, 01, 01, 01, 00, 02]
+Raw bytes (58): 0x[01, 01, 02, 05, 01, 01, 0d, 0a, 01, 0e, 01, 00, 0a, 02, 01, 09, 00, 0c, 01, 00, 10, 00, 1b, 02, 00, 1c, 00, 28, 01, 02, 08, 00, 23, 09, 00, 29, 00, 44, 0d, 00, 47, 02, 06, 06, 02, 05, 00, 06, 01, 02, 05, 00, 0b, 01, 01, 01, 00, 02]
 Number of files: 1
 - file 0 => $DIR/unicode.rs
 Number of expressions: 2
@@ -9,7 +9,7 @@ Number of file 0 mappings: 10
 - Code(Counter(0)) at (prev + 14, 1) to (start + 0, 10)
 - Code(Expression(0, Sub)) at (prev + 1, 9) to (start + 0, 12)
     = (c1 - c0)
-- Code(Counter(1)) at (prev + 0, 16) to (start + 0, 27)
+- Code(Counter(0)) at (prev + 0, 16) to (start + 0, 27)
 - Code(Expression(0, Sub)) at (prev + 0, 28) to (start + 0, 40)
     = (c1 - c0)
 - Code(Counter(0)) at (prev + 2, 8) to (start + 0, 35)
diff --git a/tests/coverage/unicode.coverage b/tests/coverage/unicode.coverage
index 4646cc92e8e42..188848889d30c 100644
--- a/tests/coverage/unicode.coverage
+++ b/tests/coverage/unicode.coverage
@@ -12,8 +12,8 @@
    LL|       |// points or bytes.
    LL|       |
    LL|      1|fn main() {
-   LL|     33|    for _İ in 'А'..='Я' { /* Я */ }
-                      ^32                ^32
+   LL|     32|    for _İ in 'А'..='Я' { /* Я */ }
+                             ^1
    LL|       |
    LL|      1|    if 申し訳ございません() && 申し訳ございません() {
                                                       ^0
diff --git a/tests/ui/for/iter_from_mac_call.rs b/tests/ui/for/iter_from_mac_call.rs
new file mode 100644
index 0000000000000..8df21456222c4
--- /dev/null
+++ b/tests/ui/for/iter_from_mac_call.rs
@@ -0,0 +1,26 @@
+macro_rules! deref {
+    ($e:expr) => { *$e };
+}
+
+fn f1<'a>(mut iter: Box<dyn Iterator<Item=&'a mut u8>>) {
+    for item in deref!(iter) { *item = 0 }
+    //~^ ERROR `dyn Iterator<Item = &'a mut u8>` is not an iterator
+}
+
+fn f2(x: &mut i32) {
+    for _item in deref!(x) {}
+    //~^ ERROR `i32` is not an iterator
+}
+
+struct Wrapped(i32);
+
+macro_rules! borrow_deref {
+    ($e:expr) => { &mut *$e };
+}
+
+fn f3<'a>(mut iter: Box<dyn Iterator<Item=&'a mut i32>>) {
+    for Wrapped(item) in borrow_deref!(iter) { *item = 0 }
+    //~^ ERROR mismatched types
+}
+
+fn main() {}
diff --git a/tests/ui/for/iter_from_mac_call.stderr b/tests/ui/for/iter_from_mac_call.stderr
new file mode 100644
index 0000000000000..e62efb250e299
--- /dev/null
+++ b/tests/ui/for/iter_from_mac_call.stderr
@@ -0,0 +1,35 @@
+error[E0277]: `dyn Iterator<Item = &'a mut u8>` is not an iterator
+  --> $DIR/iter_from_mac_call.rs:6:17
+   |
+LL |     for item in deref!(iter) { *item = 0 }
+   |                 ^^^^^^^^^^^^ the trait `IntoIterator` is not implemented for `dyn Iterator<Item = &'a mut u8>`
+   |
+   = note: the trait bound `dyn Iterator<Item = &'a mut u8>: IntoIterator` is not satisfied
+   = note: required for `dyn Iterator<Item = &'a mut u8>` to implement `IntoIterator`
+help: consider mutably borrowing here
+   |
+LL |     for item in &mut deref!(iter) { *item = 0 }
+   |                 ++++
+
+error[E0277]: `i32` is not an iterator
+  --> $DIR/iter_from_mac_call.rs:11:18
+   |
+LL |     for _item in deref!(x) {}
+   |                  ^^^^^^^^^ `i32` is not an iterator
+   |
+   = help: the trait `Iterator` is not implemented for `i32`
+   = note: if you want to iterate between `start` until a value `end`, use the exclusive range syntax `start..end` or the inclusive range syntax `start..=end`
+   = note: required for `i32` to implement `IntoIterator`
+
+error[E0308]: mismatched types
+  --> $DIR/iter_from_mac_call.rs:22:9
+   |
+LL |     for Wrapped(item) in borrow_deref!(iter) { *item = 0 }
+   |         ^^^^^^^^^^^^^    ------------------- this is an iterator with items of type `&mut i32`
+   |         |
+   |         expected `i32`, found `Wrapped`
+
+error: aborting due to 3 previous errors
+
+Some errors have detailed explanations: E0277, E0308.
+For more information about an error, try `rustc --explain E0277`.
diff --git a/tests/ui/traits/suggest-dereferences/invalid-suggest-deref-issue-127590.rs b/tests/ui/traits/suggest-dereferences/invalid-suggest-deref-issue-127590.rs
index a71657316ae60..ad1ff56190c2f 100644
--- a/tests/ui/traits/suggest-dereferences/invalid-suggest-deref-issue-127590.rs
+++ b/tests/ui/traits/suggest-dereferences/invalid-suggest-deref-issue-127590.rs
@@ -6,6 +6,7 @@ fn main() {
     for (src, dest) in std::iter::zip(fields.iter(), &variant.iter()) {
         //~^ ERROR `&std::slice::Iter<'_, {integer}>` is not an iterator
         //~| ERROR `&std::slice::Iter<'_, {integer}>` is not an iterator
+        //~| ERROR `&std::slice::Iter<'_, {integer}>` is not an iterator
         eprintln!("{} {}", src, dest);
     }
 
@@ -13,6 +14,7 @@ fn main() {
     for (src, dest) in std::iter::zip(fields.iter(), &variant.iter().clone()) {
         //~^ ERROR `&std::slice::Iter<'_, {integer}>` is not an iterator
         //~| ERROR `&std::slice::Iter<'_, {integer}>` is not an iterator
+        //~| ERROR `&std::slice::Iter<'_, {integer}>` is not an iterator
         eprintln!("{} {}", src, dest);
     }
 }
diff --git a/tests/ui/traits/suggest-dereferences/invalid-suggest-deref-issue-127590.stderr b/tests/ui/traits/suggest-dereferences/invalid-suggest-deref-issue-127590.stderr
index 103fb7bbfe11c..07a54d574df49 100644
--- a/tests/ui/traits/suggest-dereferences/invalid-suggest-deref-issue-127590.stderr
+++ b/tests/ui/traits/suggest-dereferences/invalid-suggest-deref-issue-127590.stderr
@@ -30,7 +30,7 @@ help: the trait `Iterator` is implemented for `std::slice::Iter<'_, T>`
    = note: this error originates in the macro `iterator` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0277]: `&std::slice::Iter<'_, {integer}>` is not an iterator
-  --> $DIR/invalid-suggest-deref-issue-127590.rs:13:54
+  --> $DIR/invalid-suggest-deref-issue-127590.rs:14:54
    |
 LL |     for (src, dest) in std::iter::zip(fields.iter(), &variant.iter().clone()) {
    |                        --------------                ^^^^^^^^^^^^^^^^^^^^^^^ `&std::slice::Iter<'_, {integer}>` is not an iterator
@@ -48,7 +48,7 @@ LL +     for (src, dest) in std::iter::zip(fields.iter(), variant.iter().clone()
    |
 
 error[E0277]: `&std::slice::Iter<'_, {integer}>` is not an iterator
-  --> $DIR/invalid-suggest-deref-issue-127590.rs:13:24
+  --> $DIR/invalid-suggest-deref-issue-127590.rs:14:24
    |
 LL |     for (src, dest) in std::iter::zip(fields.iter(), &variant.iter().clone()) {
    |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `&std::slice::Iter<'_, {integer}>` is not an iterator
@@ -60,6 +60,30 @@ help: the trait `Iterator` is implemented for `std::slice::Iter<'_, T>`
    = note: required for `Zip<std::slice::Iter<'_, {integer}>, &std::slice::Iter<'_, {integer}>>` to implement `IntoIterator`
    = note: this error originates in the macro `iterator` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error: aborting due to 4 previous errors
+error[E0277]: `&std::slice::Iter<'_, {integer}>` is not an iterator
+  --> $DIR/invalid-suggest-deref-issue-127590.rs:6:24
+   |
+LL |     for (src, dest) in std::iter::zip(fields.iter(), &variant.iter()) {
+   |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `&std::slice::Iter<'_, {integer}>` is not an iterator
+   |
+   = help: the trait `Iterator` is not implemented for `&std::slice::Iter<'_, {integer}>`
+help: the trait `Iterator` is implemented for `std::slice::Iter<'_, T>`
+  --> $SRC_DIR/core/src/slice/iter.rs:LL:COL
+   = note: required for `&std::slice::Iter<'_, {integer}>` to implement `IntoIterator`
+   = note: this error originates in the macro `iterator` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: `&std::slice::Iter<'_, {integer}>` is not an iterator
+  --> $DIR/invalid-suggest-deref-issue-127590.rs:14:24
+   |
+LL |     for (src, dest) in std::iter::zip(fields.iter(), &variant.iter().clone()) {
+   |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `&std::slice::Iter<'_, {integer}>` is not an iterator
+   |
+   = help: the trait `Iterator` is not implemented for `&std::slice::Iter<'_, {integer}>`
+help: the trait `Iterator` is implemented for `std::slice::Iter<'_, T>`
+  --> $SRC_DIR/core/src/slice/iter.rs:LL:COL
+   = note: required for `&std::slice::Iter<'_, {integer}>` to implement `IntoIterator`
+   = note: this error originates in the macro `iterator` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to 6 previous errors
 
 For more information about this error, try `rustc --explain E0277`.