[llvm] r272427 - [x86] enable bitcasted fabs/fneg transforms

[Sanjay Patel via llvm-commits]

Author: spatel
Date: Fri Jun 10 15:33:50 2016
New Revision: 272427

URL: http://llvm.org/viewvc/llvm-project?rev=272427&view=rev
Log:
[x86] enable bitcasted fabs/fneg transforms

The vector cases don't change because we already have folds in X86ISelLowering
to look through and remove bitcasts.

Modified:
    llvm/trunk/lib/Target/X86/X86ISelLowering.h
    llvm/trunk/test/CodeGen/X86/fp-logic.ll

Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.h?rev=272427&r1=272426&r2=272427&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.h (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.h Fri Jun 10 15:33:50 2016
@@ -758,6 +758,10 @@ namespace llvm {
 
     bool isCheapToSpeculateCtlz() const override;
 
+    bool hasBitPreservingFPLogic(EVT VT) const override {
+      return VT == MVT::f32 || VT == MVT::f64 || VT.isVector();
+    }
+
     bool hasAndNotCompare(SDValue Y) const override;
 
     /// Return the value type to use for ISD::SETCC.

Modified: llvm/trunk/test/CodeGen/X86/fp-logic.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/fp-logic.ll?rev=272427&r1=272426&r2=272427&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/fp-logic.ll (original)
+++ llvm/trunk/test/CodeGen/X86/fp-logic.ll Fri Jun 10 15:33:50 2016
@@ -265,8 +265,7 @@ define float @movmsk(float %x) {
 define double @bitcast_fabs(double %x) {
 ; CHECK-LABEL: bitcast_fabs:
 ; CHECK:       # BB#0:
-; CHECK-NEXT:    movsd {{.*#+}} xmm1 = mem[0],zero
-; CHECK-NEXT:    andpd %xmm1, %xmm0
+; CHECK-NEXT:    andpd {{.*}}(%rip), %xmm0
 ; CHECK-NEXT:    retq
 ;
   %bc1 = bitcast double %x to i64
@@ -278,8 +277,7 @@ define double @bitcast_fabs(double %x) {
 define float @bitcast_fneg(float %x) {
 ; CHECK-LABEL: bitcast_fneg:
 ; CHECK:       # BB#0:
-; CHECK-NEXT:    movss {{.*#+}} xmm1 = mem[0],zero,zero,zero
-; CHECK-NEXT:    xorps %xmm1, %xmm0
+; CHECK-NEXT:    xorps {{.*}}(%rip), %xmm0
 ; CHECK-NEXT:    retq
 ;
   %bc1 = bitcast float %x to i32