[X86] Invalid fp16 comparison fix

[azwolski]

Missing VCMPPHZrrik, VCMPPHZ128rrik, and VCMPPHZ256rrik opcodes in commuteInstructionImpl and findCommutedOpIndices led to improper handling of compare instruction during optimization. Operands were commuted, but swapping of the immediate was not called.

Fixes: #159723

[phoebewang]

LGTM.

[llvmbot]

@llvm/pr-subscribers-backend-x86

Author: None (azwolski)

Changes

Missing VCMPPHZrrik, VCMPPHZ128rrik, and VCMPPHZ256rrik opcodes in commuteInstructionImpl and findCommutedOpIndices led to improper handling of compare instruction during optimization. Operands were commuted, but swapping of the immediate was not called.

Fixes: #159723

---

Full diff: https://github.com/llvm/llvm-project/pull/160304.diff

2 Files Affected:

• (modified) llvm/lib/Target/X86/X86InstrInfo.cpp (+7-1)
• (modified) llvm/test/CodeGen/X86/pr159723.ll (+3-3)

diff --git a/llvm/lib/Target/X86/X86InstrInfo.cpp b/llvm/lib/Target/X86/X86InstrInfo.cpp
index 58d526269ff3c..497441d8b6f93 100644
--- a/llvm/lib/Target/X86/X86InstrInfo.cpp
+++ b/llvm/lib/Target/X86/X86InstrInfo.cpp
@@ -2573,10 +2573,13 @@ MachineInstr *X86InstrInfo::commuteInstructionImpl(MachineInstr &MI, bool NewMI,
   case X86::VCMPPSZ256rri:
   case X86::VCMPPDZrrik:
   case X86::VCMPPSZrrik:
+  case X86::VCMPPHZrrik:
   case X86::VCMPPDZ128rrik:
   case X86::VCMPPSZ128rrik:
+  case X86::VCMPPHZ128rrik:
   case X86::VCMPPDZ256rrik:
   case X86::VCMPPSZ256rrik:
+  case X86::VCMPPHZ256rrik:
     WorkingMI = CloneIfNew(MI);
     WorkingMI->getOperand(MI.getNumExplicitOperands() - 1)
         .setImm(X86::getSwappedVCMPImm(
@@ -2830,10 +2833,13 @@ bool X86InstrInfo::findCommutedOpIndices(const MachineInstr &MI,
   case X86::VCMPPSZ256rri:
   case X86::VCMPPDZrrik:
   case X86::VCMPPSZrrik:
+  case X86::VCMPPHZrrik:
   case X86::VCMPPDZ128rrik:
   case X86::VCMPPSZ128rrik:
+  case X86::VCMPPHZ128rrik:
   case X86::VCMPPDZ256rrik:
-  case X86::VCMPPSZ256rrik: {
+  case X86::VCMPPSZ256rrik:
+  case X86::VCMPPHZ256rrik: {
     unsigned OpOffset = X86II::isKMasked(Desc.TSFlags) ? 1 : 0;
 
     // Float comparison can be safely commuted for
diff --git a/llvm/test/CodeGen/X86/pr159723.ll b/llvm/test/CodeGen/X86/pr159723.ll
index cab4abb043639..c66b101fff990 100644
--- a/llvm/test/CodeGen/X86/pr159723.ll
+++ b/llvm/test/CodeGen/X86/pr159723.ll
@@ -17,7 +17,7 @@ define <8 x i1> @test_cmp_v8half_ogt(<8 x half> %rhs, <8 x i1> %mask) nounwind {
 ; CHECK-NEXT:    kmovw %k1, {{[-0-9]+}}(%r{{[sb]}}p) # 2-byte Spill
 ; CHECK-NEXT:    callq test_call_8@PLT
 ; CHECK-NEXT:    kmovw {{[-0-9]+}}(%r{{[sb]}}p), %k1 # 2-byte Reload
-; CHECK-NEXT:    vcmpltph {{[-0-9]+}}(%r{{[sb]}}p), %xmm0, %k0 {%k1} # 16-byte Folded Reload
+; CHECK-NEXT:    vcmpgtph {{[-0-9]+}}(%r{{[sb]}}p), %xmm0, %k0 {%k1} # 16-byte Folded Reload
 ; CHECK-NEXT:    vpmovm2w %k0, %xmm0
 ; CHECK-NEXT:    addq $40, %rsp
 ; CHECK-NEXT:    retq
@@ -79,7 +79,7 @@ define <16 x i1> @test_cmp_v16half_olt_commute(<16 x half> %rhs, <16 x i1> %mask
 ; CHECK-NEXT:    kmovw %k1, {{[-0-9]+}}(%r{{[sb]}}p) # 2-byte Spill
 ; CHECK-NEXT:    callq test_call_16@PLT
 ; CHECK-NEXT:    kmovw {{[-0-9]+}}(%r{{[sb]}}p), %k1 # 2-byte Reload
-; CHECK-NEXT:    vcmpltph {{[-0-9]+}}(%r{{[sb]}}p), %ymm0, %k0 {%k1} # 32-byte Folded Reload
+; CHECK-NEXT:    vcmpgtph {{[-0-9]+}}(%r{{[sb]}}p), %ymm0, %k0 {%k1} # 32-byte Folded Reload
 ; CHECK-NEXT:    vpmovm2b %k0, %xmm0
 ; CHECK-NEXT:    addq $56, %rsp
 ; CHECK-NEXT:    vzeroupper
@@ -100,7 +100,7 @@ define <32 x i1> @test_cmp_v32half_oge(<32 x half> %rhs, <32 x i1> %mask) nounwi
 ; CHECK-NEXT:    kmovd %k1, {{[-0-9]+}}(%r{{[sb]}}p) # 4-byte Spill
 ; CHECK-NEXT:    callq test_call_32@PLT
 ; CHECK-NEXT:    kmovd {{[-0-9]+}}(%r{{[sb]}}p), %k1 # 4-byte Reload
-; CHECK-NEXT:    vcmpleph {{[-0-9]+}}(%r{{[sb]}}p), %zmm0, %k0 {%k1} # 64-byte Folded Reload
+; CHECK-NEXT:    vcmpgeph {{[-0-9]+}}(%r{{[sb]}}p), %zmm0, %k0 {%k1} # 64-byte Folded Reload
 ; CHECK-NEXT:    vpmovm2b %k0, %ymm0
 ; CHECK-NEXT:    addq $88, %rsp
 ; CHECK-NEXT:    retq

[e-kud]

LGTM. Thanks!

[RKSimon]

LGTM - cheers