RPCS3/llvm-mirror
1
0
Fork 0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-23 03:02:36 +01:00
Code Issues Projects Releases Wiki Activity

refactor of visitFADD for AllowNewConst cases

Browse Source 
Summary: Refactoring for all constant cases which require AllowNewConst and some staging for future fmf usage.

Reviewers: spatel, hfinkel, wristow

Reviewed By: spatel

Subscribers: nhaehnle

Differential Revision: https://reviews.llvm.org/D48289

llvm-svn: 334984
This commit is contained in:
Michael Berg 2018-06-18 21:12:21 +00:00
parent 14aa992de5
commit 93992cb417
1 changed files with 20 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

37
lib/CodeGen/SelectionDAG/DAGCombiner.cpp
View File

@ -10335,12 +10335,24 @@ SDValue DAGCombiner::visitFADD(SDNode *N) {
return N0;
}
// If 'unsafe math' is enabled, fold lots of things.
if (Options.UnsafeFPMath) {
// No FP constant should be created after legalization as Instruction
// Selection pass has a hard time dealing with FP constants.
bool AllowNewConst = (Level < AfterLegalizeDAG);
// No FP constant should be created after legalization as Instruction
// Selection pass has a hard time dealing with FP constants.
bool AllowNewConst = (Level < AfterLegalizeDAG);
// TODO: fmf test for NaNs could be done here too
if (Options.UnsafeFPMath && AllowNewConst) {
// If allowed, fold (fadd (fneg x), x) -> 0.0
if (N0.getOpcode() == ISD::FNEG && N0.getOperand(0) == N1)
return DAG.getConstantFP(0.0, DL, VT);
// If allowed, fold (fadd x, (fneg x)) -> 0.0
if (N1.getOpcode() == ISD::FNEG && N1.getOperand(0) == N0)
return DAG.getConstantFP(0.0, DL, VT);
}
// If 'unsafe math' is enabled, fold lots of things.
// TODO: fmf testing for reassoc/nsz could be done here too
if (Options.UnsafeFPMath && AllowNewConst) {
// fadd (fadd x, c1), c2 -> fadd x, c1 + c2
if (N1CFP && N0.getOpcode() == ISD::FADD &&
isConstantFPBuildVectorOrConstantFP(N0.getOperand(1))) {
@ -10348,14 +10360,6 @@ SDValue DAGCombiner::visitFADD(SDNode *N) {
return DAG.getNode(ISD::FADD, DL, VT, N0.getOperand(0), NewC, Flags);
}
// If allowed, fold (fadd (fneg x), x) -> 0.0
if (AllowNewConst && N0.getOpcode() == ISD::FNEG && N0.getOperand(0) == N1)
return DAG.getConstantFP(0.0, DL, VT);
// If allowed, fold (fadd x, (fneg x)) -> 0.0
if (AllowNewConst && N1.getOpcode() == ISD::FNEG && N1.getOperand(0) == N0)
return DAG.getConstantFP(0.0, DL, VT);
// We can fold chains of FADD's of the same value into multiplications.
// This transform is not safe in general because we are reducing the number
// of rounding steps.
@ -10402,7 +10406,7 @@ SDValue DAGCombiner::visitFADD(SDNode *N) {
}
}
if (N0.getOpcode() == ISD::FADD && AllowNewConst) {
if (N0.getOpcode() == ISD::FADD) {
bool CFP00 = isConstantFPBuildVectorOrConstantFP(N0.getOperand(0));
// (fadd (fadd x, x), x) -> (fmul x, 3.0)
if (!CFP00 && N0.getOperand(0) == N0.getOperand(1) &&
@ -10412,7 +10416,7 @@ SDValue DAGCombiner::visitFADD(SDNode *N) {
}
}
if (N1.getOpcode() == ISD::FADD && AllowNewConst) {
if (N1.getOpcode() == ISD::FADD) {
bool CFP10 = isConstantFPBuildVectorOrConstantFP(N1.getOperand(0));
// (fadd x, (fadd x, x)) -> (fmul x, 3.0)
if (!CFP10 && N1.getOperand(0) == N1.getOperand(1) &&
@ -10423,8 +10427,7 @@ SDValue DAGCombiner::visitFADD(SDNode *N) {
}
// (fadd (fadd x, x), (fadd x, x)) -> (fmul x, 4.0)
if (AllowNewConst &&
N0.getOpcode() == ISD::FADD && N1.getOpcode() == ISD::FADD &&
if (N0.getOpcode() == ISD::FADD && N1.getOpcode() == ISD::FADD &&
N0.getOperand(0) == N0.getOperand(1) &&
N1.getOperand(0) == N1.getOperand(1) &&
N0.getOperand(0) == N1.getOperand(0)) {