[llvm] r371775 - [DAGCombiner][X86] Pass the CmpOpVT to reduceSelectOfFPConstantLoads so X86 can exclude fp128 compares.

[Craig Topper via llvm-commits]

Author: ctopper
Date: Thu Sep 12 14:30:18 2019
New Revision: 371775

URL: http://llvm.org/viewvc/llvm-project?rev=371775&view=rev
Log:
[DAGCombiner][X86] Pass the CmpOpVT to reduceSelectOfFPConstantLoads so X86 can exclude fp128 compares.

The X86 decision assumes the compare will produce a result in an XMM
register, but that can't happen for an fp128 compare since those
go to a libcall the returns an i32. Pass the VT so X86 can check
the type.

Modified:
    llvm/trunk/include/llvm/CodeGen/TargetLowering.h
    llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
    llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
    llvm/trunk/lib/Target/X86/X86ISelLowering.h
    llvm/trunk/test/CodeGen/X86/fp128-i128.ll

Modified: llvm/trunk/include/llvm/CodeGen/TargetLowering.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/TargetLowering.h?rev=371775&r1=371774&r2=371775&view=diff
==============================================================================
--- llvm/trunk/include/llvm/CodeGen/TargetLowering.h (original)
+++ llvm/trunk/include/llvm/CodeGen/TargetLowering.h Thu Sep 12 14:30:18 2019
@@ -284,7 +284,7 @@ public:
   /// a constant pool load whose address depends on the select condition. The
   /// parameter may be used to differentiate a select with FP compare from
   /// integer compare.
-  virtual bool reduceSelectOfFPConstantLoads(bool IsFPSetCC) const {
+  virtual bool reduceSelectOfFPConstantLoads(EVT CmpOpVT) const {
     return true;
   }
 

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp?rev=371775&r1=371774&r2=371775&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Thu Sep 12 14:30:18 2019
@@ -20036,7 +20036,7 @@ SDValue DAGCombiner::foldSelectCCToShift
 SDValue DAGCombiner::convertSelectOfFPConstantsToLoadOffset(
     const SDLoc &DL, SDValue N0, SDValue N1, SDValue N2, SDValue N3,
     ISD::CondCode CC) {
-  if (!TLI.reduceSelectOfFPConstantLoads(N0.getValueType().isFloatingPoint()))
+  if (!TLI.reduceSelectOfFPConstantLoads(N0.getValueType()))
     return SDValue();
 
   // If we are before legalize types, we want the other legalization to happen

Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=371775&r1=371774&r2=371775&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Thu Sep 12 14:30:18 2019
@@ -4915,11 +4915,12 @@ bool X86TargetLowering::shouldConvertCon
   return true;
 }
 
-bool X86TargetLowering::reduceSelectOfFPConstantLoads(bool IsFPSetCC) const {
+bool X86TargetLowering::reduceSelectOfFPConstantLoads(EVT CmpOpVT) const {
   // If we are using XMM registers in the ABI and the condition of the select is
   // a floating-point compare and we have blendv or conditional move, then it is
   // cheaper to select instead of doing a cross-register move and creating a
   // load that depends on the compare result.
+  bool IsFPSetCC = CmpOpVT.isFloatingPoint() && CmpOpVT != MVT::f128;
   return !IsFPSetCC || !Subtarget.isTarget64BitLP64() || !Subtarget.hasAVX();
 }
 

Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.h?rev=371775&r1=371774&r2=371775&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.h (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.h Thu Sep 12 14:30:18 2019
@@ -1103,7 +1103,7 @@ namespace llvm {
     bool shouldConvertConstantLoadToIntImm(const APInt &Imm,
                                            Type *Ty) const override;
 
-    bool reduceSelectOfFPConstantLoads(bool IsFPSetCC) const override;
+    bool reduceSelectOfFPConstantLoads(EVT CmpOpVT) const override;
 
     bool convertSelectOfConstantsToMath(EVT VT) const override;
 

Modified: llvm/trunk/test/CodeGen/X86/fp128-i128.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/fp128-i128.ll?rev=371775&r1=371774&r2=371775&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/fp128-i128.ll (original)
+++ llvm/trunk/test/CodeGen/X86/fp128-i128.ll Thu Sep 12 14:30:18 2019
@@ -160,14 +160,11 @@ define fp128 @TestI128_1(fp128 %x) #0 {
 ; AVX-NEXT:    vmovaps (%rsp), %xmm0
 ; AVX-NEXT:    vmovaps {{.*}}(%rip), %xmm1
 ; AVX-NEXT:    callq __lttf2
+; AVX-NEXT:    xorl %ecx, %ecx
 ; AVX-NEXT:    testl %eax, %eax
-; AVX-NEXT:    js .LBB2_1
-; AVX-NEXT:  # %bb.2: # %entry
-; AVX-NEXT:    vmovaps {{.*}}(%rip), %xmm0
-; AVX-NEXT:    addq $40, %rsp
-; AVX-NEXT:    retq
-; AVX-NEXT:  .LBB2_1:
-; AVX-NEXT:    vmovaps {{.*}}(%rip), %xmm0
+; AVX-NEXT:    sets %cl
+; AVX-NEXT:    shlq $4, %rcx
+; AVX-NEXT:    vmovaps {{\.LCPI.*}}(%rcx), %xmm0
 ; AVX-NEXT:    addq $40, %rsp
 ; AVX-NEXT:    retq
 entry: