[GISel]: Add Opcodes for CTLZ/CTTZ/CTPOP

https://reviews.llvm.org/D48600

Added IRTranslator support to translate these known intrinsics into GISel opcodes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@338944 91177308-0d34-0410-b5e6-96231b3b80d8
(cherry picked from commit a347456)

Author: Aditya Nandakumar

include/llvm/Support/TargetOpcodes.def

@@ -464,6 +464,21 @@ HANDLE_TARGET_OPCODE(G_EXTRACT_VECTOR_ELT)
 /// Generic shufflevector.
 HANDLE_TARGET_OPCODE(G_SHUFFLE_VECTOR)
 
+/// Generic count trailing zeroes.
+HANDLE_TARGET_OPCODE(G_CTTZ)
+
+/// Same as above, undefined for zero inputs.
+HANDLE_TARGET_OPCODE(G_CTTZ_ZERO_UNDEF)
+
+/// Generic count leading zeroes.
+HANDLE_TARGET_OPCODE(G_CTLZ)
+
+/// Same as above, undefined for zero inputs.
+HANDLE_TARGET_OPCODE(G_CTLZ_ZERO_UNDEF)
+
+/// Generic count bits.
+HANDLE_TARGET_OPCODE(G_CTPOP)
+
 /// Generic byte swap.
 HANDLE_TARGET_OPCODE(G_BSWAP)
 

include/llvm/Target/GenericOpcodes.td

@@ -120,6 +120,36 @@ def G_VAARG : GenericInstruction {
   let mayStore = 1;
 }
 
+def G_CTLZ : GenericInstruction {
+  let OutOperandList = (outs type0:$dst);
+  let InOperandList = (ins type0:$src);
+  let hasSideEffects = 0;
+}
+
+def G_CTLZ_ZERO_UNDEF : GenericInstruction {
+  let OutOperandList = (outs type0:$dst);
+  let InOperandList = (ins type0:$src);
+  let hasSideEffects = 0;
+}
+
+def G_CTTZ : GenericInstruction {
+  let OutOperandList = (outs type0:$dst);
+  let InOperandList = (ins type0:$src);
+  let hasSideEffects = 0;
+}
+
+def G_CTTZ_ZERO_UNDEF : GenericInstruction {
+  let OutOperandList = (outs type0:$dst);
+  let InOperandList = (ins type0:$src);
+  let hasSideEffects = 0;
+}
+
+def G_CTPOP : GenericInstruction {
+  let OutOperandList = (outs type0:$dst);
+  let InOperandList = (ins type0:$src);
+  let hasSideEffects = 0;
+}
+
 def G_BSWAP : GenericInstruction {
   let OutOperandList = (outs type0:$dst);
   let InOperandList = (ins type0:$src);

lib/CodeGen/GlobalISel/IRTranslator.cpp

@@ -913,6 +913,26 @@ bool IRTranslator::translateKnownIntrinsic(const CallInst &CI, Intrinsic::ID ID,
             PtrTy.getSizeInBits() / 8, 8));
     return true;
   }
+  case Intrinsic::cttz:
+  case Intrinsic::ctlz: {
+    ConstantInt *Cst = cast<ConstantInt>(CI.getArgOperand(1));
+    bool isTrailing = ID == Intrinsic::cttz;
+    unsigned Opcode = isTrailing
+                          ? Cst->isZero() ? TargetOpcode::G_CTTZ
+                                          : TargetOpcode::G_CTTZ_ZERO_UNDEF
+                          : Cst->isZero() ? TargetOpcode::G_CTLZ
+                                          : TargetOpcode::G_CTLZ_ZERO_UNDEF;
+    MIRBuilder.buildInstr(Opcode)
+        .addDef(getOrCreateVReg(CI))
+        .addUse(getOrCreateVReg(*CI.getArgOperand(0)));
+    return true;
+  }
+  case Intrinsic::ctpop: {
+    MIRBuilder.buildInstr(TargetOpcode::G_CTPOP)
+        .addDef(getOrCreateVReg(CI))
+        .addUse(getOrCreateVReg(*CI.getArgOperand(0)));
+    return true;
+  }
   }
   return false;
 }

test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll

@@ -1408,6 +1408,36 @@ define float @test_fabs_intrin(float %a) {
   ret float %res
 }
 
+declare i32 @llvm.ctlz.i32(i32, i1)
+define i32 @test_ctlz_intrinsic_zero_not_undef(i32 %a) {
+; CHECK-LABEL: name: test_ctlz_intrinsic_zero_not_undef
+; CHECK: [[A:%[0-9]+]]:_(s32) = COPY $w0
+; CHECK: [[RES:%[0-9]+]]:_(s32) = G_CTLZ [[A]]
+; CHECK: $w0 = COPY [[RES]]
+  %res = call i32 @llvm.ctlz.i32(i32 %a, i1 0)
+  ret i32 %res
+}
+
+declare i32 @llvm.cttz.i32(i32, i1)
+define i32 @test_cttz_intrinsic_zero_undef(i32 %a) {
+; CHECK-LABEL: name: test_cttz_intrinsic_zero_undef
+; CHECK: [[A:%[0-9]+]]:_(s32) = COPY $w0
+; CHECK: [[RES:%[0-9]+]]:_(s32) = G_CTTZ_ZERO_UNDEF [[A]]
+; CHECK: $w0 = COPY [[RES]]
+  %res = call i32 @llvm.cttz.i32(i32 %a, i1 1)
+  ret i32 %res
+}
+
+declare i32 @llvm.ctpop.i32(i32)
+define i32 @test_ctpop_intrinsic(i32 %a) {
+; CHECK-LABEL: name: test_ctpop
+; CHECK: [[A:%[0-9]+]]:_(s32) = COPY $w0
+; CHECK: [[RES:%[0-9]+]]:_(s32) = G_CTPOP [[A]]
+; CHECK: $w0 = COPY [[RES]]
+  %res = call i32 @llvm.ctpop.i32(i32 %a)
+  ret i32 %res
+}
+
 declare void @llvm.lifetime.start.p0i8(i64, i8*)
 declare void @llvm.lifetime.end.p0i8(i64, i8*)
 define void @test_lifetime_intrin() {

test/CodeGen/AArch64/GlobalISel/legalizer-info-validation.mir

@@ -282,6 +282,21 @@
 # DEBUG-NEXT: G_SHUFFLE_VECTOR (opcode {{[0-9]+}}): 3 type indices
 # DEBUG:      .. type index coverage check SKIPPED: no rules defined
 #
+# DEBUG-NEXT: G_CTTZ (opcode {{[0-9]+}}): 1 type index
+# DEBUG:      .. type index coverage check SKIPPED: no rules defined
+#
+# DEBUG-NEXT: G_CTTZ_ZERO_UNDEF (opcode {{[0-9]+}}): 1 type index
+# DEBUG:      .. type index coverage check SKIPPED: no rules defined
+#
+# DEBUG-NEXT: G_CTLZ (opcode {{[0-9]+}}): 1 type index
+# DEBUG:      .. type index coverage check SKIPPED: no rules defined
+#
+# DEBUG-NEXT: G_CTLZ_ZERO_UNDEF (opcode {{[0-9]+}}): 1 type index
+# DEBUG:      .. type index coverage check SKIPPED: no rules defined
+#
+# DEBUG-NEXT: G_CTPOP (opcode {{[0-9]+}}): 1 type index
+# DEBUG:      .. type index coverage check SKIPPED: no rules defined
+#
 # DEBUG-NEXT: G_BSWAP (opcode {{[0-9]+}}): 1 type index
 # DEBUG:      .. the first uncovered type index: 1, OK
 

test/TableGen/trydecode-emission.td

@@ -34,10 +34,10 @@ def InstB : TestInstruction {
 }
 
 // CHECK:      /* 0 */       MCD::OPC_ExtractField, 4, 4,  // Inst{7-4} ...
-// CHECK-NEXT: /* 3 */       MCD::OPC_FilterValue, 0, 16, 0, 0, // Skip to: 24
-// CHECK-NEXT: /* 8 */       MCD::OPC_CheckField, 2, 2, 0, 6, 0, 0, // Skip to: 21
-// CHECK-NEXT: /* 15 */      MCD::OPC_TryDecode, {{[0-9]+}}, 0, 0, 0, 0, // Opcode: InstB, skip to: 21
-// CHECK-NEXT: /* 21 */      MCD::OPC_Decode, {{[0-9]+}}, 1, // Opcode: InstA
-// CHECK-NEXT: /* 24 */      MCD::OPC_Fail,
+// CHECK-NEXT: /* 3 */       MCD::OPC_FilterValue, 0, 18, 0, 0, // Skip to: 26
+// CHECK-NEXT: /* 8 */       MCD::OPC_CheckField, 2, 2, 0, 7, 0, 0, // Skip to: 22
+// CHECK-NEXT: /* 15 */      MCD::OPC_TryDecode, {{[0-9]+}}, 1, 0, 0, 0, 0, // Opcode: InstB, skip to: 22
+// CHECK-NEXT: /* 22 */      MCD::OPC_Decode, {{[0-9]+}}, 1, 1, // Opcode: InstA
+// CHECK-NEXT: /* 26 */      MCD::OPC_Fail,
 
 // CHECK: if (DecodeInstB(MI, insn, Address, Decoder) == MCDisassembler::Fail) { DecodeComplete = false; return MCDisassembler::Fail; }

test/TableGen/trydecode-emission2.td

@@ -31,14 +31,14 @@ def InstB : TestInstruction {
 }
 
 // CHECK:      /* 0 */       MCD::OPC_ExtractField, 2, 1,  // Inst{2} ...
-// CHECK-NEXT: /* 3 */       MCD::OPC_FilterValue, 0, 34, 0, 0, // Skip to: 42
+// CHECK-NEXT: /* 3 */       MCD::OPC_FilterValue, 0, 36, 0, 0, // Skip to: 44
 // CHECK-NEXT: /* 8 */       MCD::OPC_ExtractField, 5, 3,  // Inst{7-5} ...
-// CHECK-NEXT: /* 11 */      MCD::OPC_FilterValue, 0, 26, 0, 0, // Skip to: 42
-// CHECK-NEXT: /* 16 */      MCD::OPC_CheckField, 0, 2, 3, 6, 0, 0, // Skip to: 29
-// CHECK-NEXT: /* 23 */      MCD::OPC_TryDecode, {{[0-9]+}}, 0, 0, 0, 0, // Opcode: InstB, skip to: 29
-// CHECK-NEXT: /* 29 */      MCD::OPC_CheckField, 3, 2, 0, 6, 0, 0, // Skip to: 42
-// CHECK-NEXT: /* 36 */      MCD::OPC_TryDecode, {{[0-9]+}}, 1, 0, 0, 0, // Opcode: InstA, skip to: 42
-// CHECK-NEXT: /* 42 */      MCD::OPC_Fail,
+// CHECK-NEXT: /* 11 */      MCD::OPC_FilterValue, 0, 28, 0, 0, // Skip to: 44
+// CHECK-NEXT: /* 16 */      MCD::OPC_CheckField, 0, 2, 3, 7, 0, 0, // Skip to: 30
+// CHECK-NEXT: /* 23 */      MCD::OPC_TryDecode, {{[0-9]+}}, 1, 0, 0, 0, 0, // Opcode: InstB, skip to: 30
+// CHECK-NEXT: /* 30 */      MCD::OPC_CheckField, 3, 2, 0, 7, 0, 0, // Skip to: 44
+// CHECK-NEXT: /* 37 */      MCD::OPC_TryDecode, {{[0-9]+}}, 1, 1, 0, 0, 0, // Opcode: InstA, skip to: 44
+// CHECK-NEXT: /* 44 */      MCD::OPC_Fail,
 
 // CHECK: if (DecodeInstB(MI, insn, Address, Decoder) == MCDisassembler::Fail) { DecodeComplete = false; return MCDisassembler::Fail; }
 // CHECK: if (DecodeInstA(MI, insn, Address, Decoder) == MCDisassembler::Fail) { DecodeComplete = false; return MCDisassembler::Fail; }

test/TableGen/trydecode-emission3.td

@@ -35,10 +35,10 @@ def InstB : TestInstruction {
 }
 
 // CHECK:      /* 0 */       MCD::OPC_ExtractField, 4, 4,  // Inst{7-4} ...
-// CHECK-NEXT: /* 3 */       MCD::OPC_FilterValue, 0, 16, 0, 0, // Skip to: 24
-// CHECK-NEXT: /* 8 */       MCD::OPC_CheckField, 2, 2, 0, 6, 0, 0, // Skip to: 21
-// CHECK-NEXT: /* 15 */      MCD::OPC_TryDecode, {{[0-9]+}}, 0, 0, 0, 0, // Opcode: InstB, skip to: 21
-// CHECK-NEXT: /* 21 */      MCD::OPC_Decode, {{[0-9]+}}, 1, // Opcode: InstA
-// CHECK-NEXT: /* 24 */      MCD::OPC_Fail,
+// CHECK-NEXT: /* 3 */       MCD::OPC_FilterValue, 0, 18, 0, 0, // Skip to: 26
+// CHECK-NEXT: /* 8 */       MCD::OPC_CheckField, 2, 2, 0, 7, 0, 0, // Skip to: 22
+// CHECK-NEXT: /* 15 */      MCD::OPC_TryDecode, {{[0-9]+}}, 1, 0, 0, 0, 0, // Opcode: InstB, skip to: 22
+// CHECK-NEXT: /* 22 */      MCD::OPC_Decode, {{[0-9]+}}, 1, 1, // Opcode: InstA
+// CHECK-NEXT: /* 26 */      MCD::OPC_Fail,
 
 // CHECK: if (DecodeInstBOp(MI, tmp, Address, Decoder) == MCDisassembler::Fail) { DecodeComplete = false; return MCDisassembler::Fail; }