[llvm-commits] [llvm] r46344 - in /llvm/trunk: lib/Target/X86/X86ISelLowering.cpp test/CodeGen/X86/copysign-zero.ll
Chris Lattner
sabre at nondot.org
Thu Jan 24 21:46:26 PST 2008
Author: lattner
Date: Thu Jan 24 23:46:26 2008
New Revision: 46344
URL: http://llvm.org/viewvc/llvm-project?rev=46344&view=rev
Log:
Add target-specific dag combines for FAND(x,0) and FOR(x,0). This allows
us to compile:
double test(double X) {
return copysign(0.0, X);
}
into:
_test:
andpd LCPI1_0(%rip), %xmm0
ret
instead of:
_test:
pxor %xmm1, %xmm1
andpd LCPI1_0(%rip), %xmm1
movapd %xmm0, %xmm2
andpd LCPI1_1(%rip), %xmm2
movapd %xmm1, %xmm0
orpd %xmm2, %xmm0
ret
Added:
llvm/trunk/test/CodeGen/X86/copysign-zero.ll
Modified:
llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=46344&r1=46343&r2=46344&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Thu Jan 24 23:46:26 2008
@@ -5627,16 +5627,42 @@
return SDOperand();
}
+/// PerformFORCombine - Do target-specific dag combines on X86ISD::FOR nodes.
+static SDOperand PerformFORCombine(SDNode *N, SelectionDAG &DAG) {
+ // FOR(0.0, x) -> x
+ // FOR(x, 0.0) -> x
+ if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(N->getOperand(0)))
+ if (C->getValueAPF().isPosZero())
+ return N->getOperand(1);
+ if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(N->getOperand(1)))
+ if (C->getValueAPF().isPosZero())
+ return N->getOperand(0);
+ return SDOperand();
+}
+
+/// PerformFANDCombine - Do target-specific dag combines on X86ISD::FAND nodes.
+static SDOperand PerformFANDCombine(SDNode *N, SelectionDAG &DAG) {
+ // FAND(0.0, x) -> 0.0
+ // FAND(x, 0.0) -> 0.0
+ if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(N->getOperand(0)))
+ if (C->getValueAPF().isPosZero())
+ return N->getOperand(0);
+ if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(N->getOperand(1)))
+ if (C->getValueAPF().isPosZero())
+ return N->getOperand(1);
+ return SDOperand();
+}
+
SDOperand X86TargetLowering::PerformDAGCombine(SDNode *N,
DAGCombinerInfo &DCI) const {
SelectionDAG &DAG = DCI.DAG;
switch (N->getOpcode()) {
default: break;
- case ISD::VECTOR_SHUFFLE:
- return PerformShuffleCombine(N, DAG, Subtarget);
- case ISD::SELECT:
- return PerformSELECTCombine(N, DAG, Subtarget);
+ case ISD::VECTOR_SHUFFLE: return PerformShuffleCombine(N, DAG, Subtarget);
+ case ISD::SELECT: return PerformSELECTCombine(N, DAG, Subtarget);
+ case X86ISD::FOR: return PerformFORCombine(N, DAG);
+ case X86ISD::FAND: return PerformFANDCombine(N, DAG);
}
return SDOperand();
Added: llvm/trunk/test/CodeGen/X86/copysign-zero.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/copysign-zero.ll?rev=46344&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/X86/copysign-zero.ll (added)
+++ llvm/trunk/test/CodeGen/X86/copysign-zero.ll Thu Jan 24 23:46:26 2008
@@ -0,0 +1,14 @@
+; RUN: llvm-as < %s | llc | not grep orpd
+; RUN: llvm-as < %s | llc | grep andpd | count 1
+
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128"
+target triple = "x86_64-apple-darwin8"
+
+define double @test(double %X) nounwind {
+entry:
+ %tmp2 = tail call double @copysign( double 0.000000e+00, double %X ) nounwind readnone ; <double> [#uses=1]
+ ret double %tmp2
+}
+
+declare double @copysign(double, double) nounwind readnone
+
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