[llvm] r251203 - [DAGCombiner] Tidy up ConstantFP commutation. NFCI
Simon Pilgrim via llvm-commits
llvm-commits at lists.llvm.org
Sat Oct 24 13:06:19 PDT 2015
Author: rksimon
Date: Sat Oct 24 15:06:18 2015
New Revision: 251203
URL: http://llvm.org/viewvc/llvm-project?rev=251203&view=rev
Log:
[DAGCombiner] Tidy up ConstantFP commutation. NFCI
Move ConstantFP canonicalization of commutative instructions to start of 2-op node creation (matches integer) - simplifies constant folding code.
Modified:
llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp?rev=251203&r1=251202&r2=251203&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp Sat Oct 24 15:06:18 2015
@@ -3382,11 +3382,18 @@ SDValue SelectionDAG::getNode(unsigned O
SDValue N2, const SDNodeFlags *Flags) {
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2);
+ ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
+ ConstantFPSDNode *N2CFP = dyn_cast<ConstantFPSDNode>(N2);
// Canonicalize constant to RHS if commutative.
- if (N1C && !N2C && isCommutativeBinOp(Opcode)) {
- std::swap(N1C, N2C);
- std::swap(N1, N2);
+ if (isCommutativeBinOp(Opcode)) {
+ if (N1C && !N2C) {
+ std::swap(N1C, N2C);
+ std::swap(N1, N2);
+ } else if (N1CFP && !N2CFP) {
+ std::swap(N1CFP, N2CFP);
+ std::swap(N1, N2);
+ }
}
switch (Opcode) {
@@ -3472,37 +3479,20 @@ SDValue SelectionDAG::getNode(unsigned O
case ISD::FREM:
if (getTarget().Options.UnsafeFPMath) {
if (Opcode == ISD::FADD) {
- // 0+x --> x
- if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N1))
- if (CFP->getValueAPF().isZero())
- return N2;
// x+0 --> x
- if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N2))
- if (CFP->getValueAPF().isZero())
- return N1;
+ if (N2CFP && N2CFP->getValueAPF().isZero())
+ return N1;
} else if (Opcode == ISD::FSUB) {
// x-0 --> x
- if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N2))
- if (CFP->getValueAPF().isZero())
- return N1;
+ if (N2CFP && N2CFP->getValueAPF().isZero())
+ return N1;
} else if (Opcode == ISD::FMUL) {
- ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N1);
- SDValue V = N2;
-
- // If the first operand isn't the constant, try the second
- if (!CFP) {
- CFP = dyn_cast<ConstantFPSDNode>(N2);
- V = N1;
- }
-
- if (CFP) {
- // 0*x --> 0
- if (CFP->isZero())
- return SDValue(CFP,0);
- // 1*x --> x
- if (CFP->isExactlyValue(1.0))
- return V;
- }
+ // x*0 --> 0
+ if (N2CFP && N2CFP->isZero())
+ return N2;
+ // x*1 --> x
+ if (N2CFP && N2CFP->isExactlyValue(1.0))
+ return N1;
}
}
assert(VT.isFloatingPoint() && "This operator only applies to FP types!");
@@ -3735,14 +3725,8 @@ SDValue SelectionDAG::getNode(unsigned O
// Constant fold FP operations.
bool HasFPExceptions = TLI->hasFloatingPointExceptions();
- ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
- ConstantFPSDNode *N2CFP = dyn_cast<ConstantFPSDNode>(N2);
if (N1CFP) {
- if (!N2CFP && isCommutativeBinOp(Opcode)) {
- // Canonicalize constant to RHS if commutative.
- std::swap(N1CFP, N2CFP);
- std::swap(N1, N2);
- } else if (N2CFP) {
+ if (N2CFP) {
APFloat V1 = N1CFP->getValueAPF(), V2 = N2CFP->getValueAPF();
APFloat::opStatus s;
switch (Opcode) {
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