RPCS3/llvm
1
0
Fork 0
mirror of https://github.com/RPCS3/llvm.git synced 2024-11-25 21:00:00 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Rename ValueRequiresCast to ShouldOptimizeCast, to better reflect

Browse Source 
what it does.  Enhance it to return false to optimizing vector
sign extensions from vector comparisions, which is the idiom used
to get a splatted vector for a vector comparison.

Doing this breaks vector-casts.ll, add some compensating 
transformations to handle the important case they cover without
depending on this canonicalization.

This fixes rdar://7434900 a serious pessimization of vector compares.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95855 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2010-02-11 06:26:33 +00:00
parent 2e1cdbf92d
commit 8c5ad3a5da
4 changed files with 113 additions and 55 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
lib/Transforms/InstCombine/InstCombine.h
View File

@ -199,11 +199,12 @@ private:
SmallVectorImpl<Value*> &NewIndices);
Instruction *FoldOpIntoSelect(Instruction &Op, SelectInst *SI);
/// ValueRequiresCast - Return true if the cast from "V to Ty" actually
/// results in any code being generated. It does not require codegen if V is
/// simple enough or if the cast can be folded into other casts.
bool ValueRequiresCast(Instruction::CastOps opcode,const Value *V,
const Type *Ty);
/// ShouldOptimizeCast - Return true if the cast from "V to Ty" actually
/// results in any code being generated and is interesting to optimize out. If
/// the cast can be eliminated by some other simple transformation, we prefer
/// to do the simplification first.
bool ShouldOptimizeCast(Instruction::CastOps opcode,const Value *V,
const Type *Ty);
Instruction *visitCallSite(CallSite CS);
bool transformConstExprCastCall(CallSite CS);

118
lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
View File

@ -932,24 +932,49 @@ Instruction *InstCombiner::visitAnd(BinaryOperator &I) {
if (ICmpInst *LHS = dyn_cast<ICmpInst>(Op0))
if (Instruction *Res = FoldAndOfICmps(I, LHS, RHS))
return Res;
// If and'ing two fcmp, try combine them into one.
if (FCmpInst *LHS = dyn_cast<FCmpInst>(I.getOperand(0)))
if (FCmpInst *RHS = dyn_cast<FCmpInst>(I.getOperand(1)))
if (Instruction *Res = FoldAndOfFCmps(I, LHS, RHS))
return Res;
// fold (and (cast A), (cast B)) -> (cast (and A, B))
if (CastInst *Op0C = dyn_cast<CastInst>(Op0))
if (CastInst *Op1C = dyn_cast<CastInst>(Op1))
if (Op0C->getOpcode() == Op1C->getOpcode()) { // same cast kind ?
const Type *SrcTy = Op0C->getOperand(0)->getType();
if (SrcTy == Op1C->getOperand(0)->getType() &&
SrcTy->isIntOrIntVector() &&
// Only do this if the casts both really cause code to be generated.
ValueRequiresCast(Op0C->getOpcode(), Op0C->getOperand(0),
I.getType()) &&
ValueRequiresCast(Op1C->getOpcode(), Op1C->getOperand(0),
I.getType())) {
Value *NewOp = Builder->CreateAnd(Op0C->getOperand(0),
Op1C->getOperand(0), I.getName());
if (CastInst *Op1C = dyn_cast<CastInst>(Op1)) {
const Type *SrcTy = Op0C->getOperand(0)->getType();
if (Op0C->getOpcode() == Op1C->getOpcode() && // same cast kind ?
SrcTy == Op1C->getOperand(0)->getType() &&
SrcTy->isIntOrIntVector()) {
Value *Op0COp = Op0C->getOperand(0), *Op1COp = Op1C->getOperand(0);
// Only do this if the casts both really cause code to be generated.
if (ShouldOptimizeCast(Op0C->getOpcode(), Op0COp, I.getType()) &&
ShouldOptimizeCast(Op1C->getOpcode(), Op1COp, I.getType())) {
Value *NewOp = Builder->CreateAnd(Op0COp, Op1COp, I.getName());
return CastInst::Create(Op0C->getOpcode(), NewOp, I.getType());
}
// If this is and(cast(icmp), cast(icmp)), try to fold this even if the
// cast is otherwise not optimizable. This happens for vector sexts.
if (ICmpInst *RHS = dyn_cast<ICmpInst>(Op1COp))
if (ICmpInst *LHS = dyn_cast<ICmpInst>(Op0COp))
if (Instruction *Res = FoldAndOfICmps(I, LHS, RHS)) {
InsertNewInstBefore(Res, I);
return CastInst::Create(Op0C->getOpcode(), Res, I.getType());
}
// If this is and(cast(fcmp), cast(fcmp)), try to fold this even if the
// cast is otherwise not optimizable. This happens for vector sexts.
if (FCmpInst *RHS = dyn_cast<FCmpInst>(Op1COp))
if (FCmpInst *LHS = dyn_cast<FCmpInst>(Op0COp))
if (Instruction *Res = FoldAndOfFCmps(I, LHS, RHS)) {
InsertNewInstBefore(Res, I);
return CastInst::Create(Op0C->getOpcode(), Res, I.getType());
}
}
}
// (X >> Z) & (Y >> Z) -> (X&Y) >> Z for all shifts.
if (BinaryOperator *SI1 = dyn_cast<BinaryOperator>(Op1)) {
@ -965,13 +990,6 @@ Instruction *InstCombiner::visitAnd(BinaryOperator &I) {
}
}
// If and'ing two fcmp, try combine them into one.
if (FCmpInst *LHS = dyn_cast<FCmpInst>(I.getOperand(0))) {
if (FCmpInst *RHS = dyn_cast<FCmpInst>(I.getOperand(1)))
if (Instruction *Res = FoldAndOfFCmps(I, LHS, RHS))
return Res;
}
return Changed ? &I : 0;
}
@ -1669,37 +1687,51 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) {
if (Instruction *Res = FoldOrOfICmps(I, LHS, RHS))
return Res;
// (fcmp uno x, c) | (fcmp uno y, c) -> (fcmp uno x, y)
if (FCmpInst *LHS = dyn_cast<FCmpInst>(I.getOperand(0)))
if (FCmpInst *RHS = dyn_cast<FCmpInst>(I.getOperand(1)))
if (Instruction *Res = FoldOrOfFCmps(I, LHS, RHS))
return Res;
// fold (or (cast A), (cast B)) -> (cast (or A, B))
if (CastInst *Op0C = dyn_cast<CastInst>(Op0)) {
if (CastInst *Op1C = dyn_cast<CastInst>(Op1))
if (Op0C->getOpcode() == Op1C->getOpcode()) {// same cast kind ?
if (!isa<ICmpInst>(Op0C->getOperand(0)) ||
!isa<ICmpInst>(Op1C->getOperand(0))) {
const Type *SrcTy = Op0C->getOperand(0)->getType();
if (SrcTy == Op1C->getOperand(0)->getType() &&
SrcTy->isIntOrIntVector() &&
const Type *SrcTy = Op0C->getOperand(0)->getType();
if (SrcTy == Op1C->getOperand(0)->getType() &&
SrcTy->isIntOrIntVector()) {
Value *Op0COp = Op0C->getOperand(0), *Op1COp = Op1C->getOperand(0);
if ((!isa<ICmpInst>(Op0COp) || !isa<ICmpInst>(Op1COp)) &&
// Only do this if the casts both really cause code to be
// generated.
ValueRequiresCast(Op0C->getOpcode(), Op0C->getOperand(0),
I.getType()) &&
ValueRequiresCast(Op1C->getOpcode(), Op1C->getOperand(0),
I.getType())) {
Value *NewOp = Builder->CreateOr(Op0C->getOperand(0),
Op1C->getOperand(0), I.getName());
ShouldOptimizeCast(Op0C->getOpcode(), Op0COp, I.getType()) &&
ShouldOptimizeCast(Op1C->getOpcode(), Op1COp, I.getType())) {
Value *NewOp = Builder->CreateOr(Op0COp, Op1COp, I.getName());
return CastInst::Create(Op0C->getOpcode(), NewOp, I.getType());
}
// If this is or(cast(icmp), cast(icmp)), try to fold this even if the
// cast is otherwise not optimizable. This happens for vector sexts.
if (ICmpInst *RHS = dyn_cast<ICmpInst>(Op1COp))
if (ICmpInst *LHS = dyn_cast<ICmpInst>(Op0COp))
if (Instruction *Res = FoldOrOfICmps(I, LHS, RHS)) {
InsertNewInstBefore(Res, I);
return CastInst::Create(Op0C->getOpcode(), Res, I.getType());
}
// If this is or(cast(fcmp), cast(fcmp)), try to fold this even if the
// cast is otherwise not optimizable. This happens for vector sexts.
if (FCmpInst *RHS = dyn_cast<FCmpInst>(Op1COp))
if (FCmpInst *LHS = dyn_cast<FCmpInst>(Op0COp))
if (Instruction *Res = FoldOrOfFCmps(I, LHS, RHS)) {
InsertNewInstBefore(Res, I);
return CastInst::Create(Op0C->getOpcode(), Res, I.getType());
}
}
}
}
// (fcmp uno x, c) | (fcmp uno y, c) -> (fcmp uno x, y)
if (FCmpInst *LHS = dyn_cast<FCmpInst>(I.getOperand(0))) {
if (FCmpInst *RHS = dyn_cast<FCmpInst>(I.getOperand(1)))
if (Instruction *Res = FoldOrOfFCmps(I, LHS, RHS))
return Res;
}
return Changed ? &I : 0;
}
@ -1986,10 +2018,10 @@ Instruction *InstCombiner::visitXor(BinaryOperator &I) {
const Type *SrcTy = Op0C->getOperand(0)->getType();
if (SrcTy == Op1C->getOperand(0)->getType() && SrcTy->isInteger() &&
// Only do this if the casts both really cause code to be generated.
ValueRequiresCast(Op0C->getOpcode(), Op0C->getOperand(0),
I.getType()) &&
ValueRequiresCast(Op1C->getOpcode(), Op1C->getOperand(0),
I.getType())) {
ShouldOptimizeCast(Op0C->getOpcode(), Op0C->getOperand(0),
I.getType()) &&
ShouldOptimizeCast(Op1C->getOpcode(), Op1C->getOperand(0),
I.getType())) {
Value *NewOp = Builder->CreateXor(Op0C->getOperand(0),
Op1C->getOperand(0), I.getName());
return CastInst::Create(Op0C->getOpcode(), NewOp, I.getType());

23
lib/Transforms/InstCombine/InstCombineCasts.cpp
View File

@ -255,17 +255,26 @@ isEliminableCastPair(
return Instruction::CastOps(Res);
}
/// ValueRequiresCast - Return true if the cast from "V to Ty" actually results
/// in any code being generated. It does not require codegen if V is simple
/// enough or if the cast can be folded into other casts.
bool InstCombiner::ValueRequiresCast(Instruction::CastOps opcode,const Value *V,
const Type *Ty) {
/// ShouldOptimizeCast - Return true if the cast from "V to Ty" actually
/// results in any code being generated and is interesting to optimize out. If
/// the cast can be eliminated by some other simple transformation, we prefer
/// to do the simplification first.
bool InstCombiner::ShouldOptimizeCast(Instruction::CastOps opc, const Value *V,
const Type *Ty) {
// Noop casts and casts of constants should be eliminated trivially.
if (V->getType() == Ty || isa<Constant>(V)) return false;
// If this is another cast that can be eliminated, it isn't codegen either.
// If this is another cast that can be eliminated, we prefer to have it
// eliminated.
if (const CastInst *CI = dyn_cast<CastInst>(V))
if (isEliminableCastPair(CI, opcode, Ty, TD))
if (isEliminableCastPair(CI, opc, Ty, TD))
return false;
// If this is a vector sext from a compare, then we don't want to break the
// idiom where each element of the extended vector is either zero or all ones.
if (opc == Instruction::SExt && isa<CmpInst>(V) && isa<VectorType>(Ty))
return false;
return true;
}

16
test/Transforms/InstCombine/vector-casts.ll
View File

@ -51,6 +51,22 @@ entry:
}
; rdar://7434900
define <2 x i64> @test5(<4 x float> %a, <4 x float> %b) nounwind readnone {
entry:
%cmp = fcmp ult <4 x float> %a, zeroinitializer
%sext = sext <4 x i1> %cmp to <4 x i32>
%cmp4 = fcmp ult <4 x float> %b, zeroinitializer
%sext5 = sext <4 x i1> %cmp4 to <4 x i32>
%and = and <4 x i32> %sext, %sext5
%conv = bitcast <4 x i32> %and to <2 x i64>
ret <2 x i64> %conv
; CHECK: @test5
; CHECK: sext <4 x i1> %cmp to <4 x i32>
; CHECK: sext <4 x i1> %cmp4 to <4 x i32>
}
define void @convert(<2 x i32>* %dst.addr, <2 x i64> %src) nounwind {
entry: