[RISCV] Add test case for missed opportunity use bgez for the canonical form X > -1. NFC

Author: topperc

llvm/test/CodeGen/RISCV/branch.ll

@@ -6,41 +6,45 @@ define void @foo(i32 %a, i32 *%b, i1 %c) nounwind {
 ; RV32I-LABEL: foo:
 ; RV32I:       # %bb.0:
 ; RV32I-NEXT:    lw a3, 0(a1)
-; RV32I-NEXT:    beq a3, a0, .LBB0_12
+; RV32I-NEXT:    beq a3, a0, .LBB0_13
 ; RV32I-NEXT:  # %bb.1: # %test2
 ; RV32I-NEXT:    lw a3, 0(a1)
-; RV32I-NEXT:    bne a3, a0, .LBB0_12
+; RV32I-NEXT:    bne a3, a0, .LBB0_13
 ; RV32I-NEXT:  # %bb.2: # %test3
 ; RV32I-NEXT:    lw a3, 0(a1)
-; RV32I-NEXT:    blt a3, a0, .LBB0_12
+; RV32I-NEXT:    blt a3, a0, .LBB0_13
 ; RV32I-NEXT:  # %bb.3: # %test4
 ; RV32I-NEXT:    lw a3, 0(a1)
-; RV32I-NEXT:    bge a3, a0, .LBB0_12
+; RV32I-NEXT:    bge a3, a0, .LBB0_13
 ; RV32I-NEXT:  # %bb.4: # %test5
 ; RV32I-NEXT:    lw a3, 0(a1)
-; RV32I-NEXT:    bltu a3, a0, .LBB0_12
+; RV32I-NEXT:    bltu a3, a0, .LBB0_13
 ; RV32I-NEXT:  # %bb.5: # %test6
 ; RV32I-NEXT:    lw a3, 0(a1)
-; RV32I-NEXT:    bgeu a3, a0, .LBB0_12
+; RV32I-NEXT:    bgeu a3, a0, .LBB0_13
 ; RV32I-NEXT:  # %bb.6: # %test7
 ; RV32I-NEXT:    lw a3, 0(a1)
-; RV32I-NEXT:    blt a0, a3, .LBB0_12
+; RV32I-NEXT:    blt a0, a3, .LBB0_13
 ; RV32I-NEXT:  # %bb.7: # %test8
 ; RV32I-NEXT:    lw a3, 0(a1)
-; RV32I-NEXT:    bge a0, a3, .LBB0_12
+; RV32I-NEXT:    bge a0, a3, .LBB0_13
 ; RV32I-NEXT:  # %bb.8: # %test9
 ; RV32I-NEXT:    lw a3, 0(a1)
-; RV32I-NEXT:    bltu a0, a3, .LBB0_12
+; RV32I-NEXT:    bltu a0, a3, .LBB0_13
 ; RV32I-NEXT:  # %bb.9: # %test10
 ; RV32I-NEXT:    lw a3, 0(a1)
-; RV32I-NEXT:    bgeu a0, a3, .LBB0_12
+; RV32I-NEXT:    bgeu a0, a3, .LBB0_13
 ; RV32I-NEXT:  # %bb.10: # %test11
 ; RV32I-NEXT:    lw a0, 0(a1)
 ; RV32I-NEXT:    andi a0, a2, 1
-; RV32I-NEXT:    bnez a0, .LBB0_12
+; RV32I-NEXT:    bnez a0, .LBB0_13
 ; RV32I-NEXT:  # %bb.11: # %test12
 ; RV32I-NEXT:    lw a0, 0(a1)
-; RV32I-NEXT:  .LBB0_12: # %end
+; RV32I-NEXT:    addi a2, zero, -1
+; RV32I-NEXT:    blt a2, a0, .LBB0_13
+; RV32I-NEXT:  # %bb.12: # %test13
+; RV32I-NEXT:    lw a0, 0(a1)
+; RV32I-NEXT:  .LBB0_13: # %end
 ; RV32I-NEXT:    ret
   %val1 = load volatile i32, i32* %b
   %tst1 = icmp eq i32 %val1, %a
@@ -100,8 +104,15 @@ test11:
   %val11 = load volatile i32, i32* %b
   br i1 %c, label %end, label %test12
 
+; Check that we use bgez for X > -1 which is the canonical form.
+
 test12:
   %val12 = load volatile i32, i32* %b
+  %tst12 = icmp sgt i32 %val12, -1
+  br i1 %tst12, label %end, label %test13
+
+test13:
+  %val13 = load volatile i32, i32* %b
   br label %end
 
 end: