[llvm-commits] [llvm] r112343 - in /llvm/trunk: lib/Transforms/InstCombine/InstCombineCasts.cpp lib/Transforms/InstCombine/InstCombineShifts.cpp test/Transforms/InstCombine/bitcast.ll
Chris Lattner
sabre at nondot.org
Fri Aug 27 18:20:38 PDT 2010
Author: lattner
Date: Fri Aug 27 20:20:38 2010
New Revision: 112343
URL: http://llvm.org/viewvc/llvm-project?rev=112343&view=rev
Log:
optimize bitcasts from large integers to vector into vector
element insertion from the pieces that feed into the vector.
This handles a pattern that occurs frequently due to code
generated for the x86-64 abi. We now compile something like
this:
struct S { float A, B, C, D; };
struct S g;
struct S bar() {
struct S A = g;
++A.A;
++A.C;
return A;
}
into all nice vector operations:
_bar: ## @bar
## BB#0: ## %entry
movq _g at GOTPCREL(%rip), %rax
movss LCPI1_0(%rip), %xmm1
movss (%rax), %xmm0
addss %xmm1, %xmm0
pshufd $16, %xmm0, %xmm0
movss 4(%rax), %xmm2
movss 12(%rax), %xmm3
pshufd $16, %xmm2, %xmm2
unpcklps %xmm2, %xmm0
addss 8(%rax), %xmm1
pshufd $16, %xmm1, %xmm1
pshufd $16, %xmm3, %xmm2
unpcklps %xmm2, %xmm1
ret
instead of icky integer operations:
_bar: ## @bar
movq _g at GOTPCREL(%rip), %rax
movss LCPI1_0(%rip), %xmm1
movss (%rax), %xmm0
addss %xmm1, %xmm0
movd %xmm0, %ecx
movl 4(%rax), %edx
movl 12(%rax), %esi
shlq $32, %rdx
addq %rcx, %rdx
movd %rdx, %xmm0
addss 8(%rax), %xmm1
movd %xmm1, %eax
shlq $32, %rsi
addq %rax, %rsi
movd %rsi, %xmm1
ret
This resolves rdar://8360454
Modified:
llvm/trunk/lib/Transforms/InstCombine/InstCombineCasts.cpp
llvm/trunk/lib/Transforms/InstCombine/InstCombineShifts.cpp
llvm/trunk/test/Transforms/InstCombine/bitcast.ll
Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineCasts.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineCasts.cpp?rev=112343&r1=112342&r2=112343&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineCasts.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineCasts.cpp Fri Aug 27 20:20:38 2010
@@ -1362,6 +1362,116 @@
return new ShuffleVectorInst(InVal, V2, Mask);
}
+static bool isMultipleOfTypeSize(unsigned Value, const Type *Ty) {
+ return Value % Ty->getPrimitiveSizeInBits() == 0;
+}
+
+static bool getTypeSizeIndex(unsigned Value, const Type *Ty) {
+ return Value / Ty->getPrimitiveSizeInBits();
+}
+
+/// CollectInsertionElements - V is a value which is inserted into a vector of
+/// VecEltTy. Look through the value to see if we can decompose it into
+/// insertions into the vector. See the example in the comment for
+/// OptimizeIntegerToVectorInsertions for the pattern this handles.
+/// The type of V is always a non-zero multiple of VecEltTy's size.
+///
+/// This returns false if the pattern can't be matched or true if it can,
+/// filling in Elements with the elements found here.
+static bool CollectInsertionElements(Value *V, unsigned ElementIndex,
+ SmallVectorImpl<Value*> &Elements,
+ const Type *VecEltTy) {
+ // If we got down to a value of the right type, we win, try inserting into the
+ // right element.
+ if (V->getType() == VecEltTy) {
+ // Fail if multiple elements are inserted into this slot.
+ if (ElementIndex >= Elements.size() || Elements[ElementIndex] != 0)
+ return false;
+
+ Elements[ElementIndex] = V;
+ return true;
+ }
+
+ //if (Constant *C = dyn_cast<Constant>(V)) {
+ // Figure out the # elements this provides, and bitcast it or slice it up
+ // as required.
+ //}
+
+ if (!V->hasOneUse()) return false;
+
+ Instruction *I = dyn_cast<Instruction>(V);
+ if (I == 0) return false;
+ switch (I->getOpcode()) {
+ default: return false; // Unhandled case.
+ case Instruction::BitCast:
+ return CollectInsertionElements(I->getOperand(0), ElementIndex,
+ Elements, VecEltTy);
+ case Instruction::ZExt:
+ if (!isMultipleOfTypeSize(
+ I->getOperand(0)->getType()->getPrimitiveSizeInBits(),
+ VecEltTy))
+ return false;
+ return CollectInsertionElements(I->getOperand(0), ElementIndex,
+ Elements, VecEltTy);
+ case Instruction::Or:
+ return CollectInsertionElements(I->getOperand(0), ElementIndex,
+ Elements, VecEltTy) &&
+ CollectInsertionElements(I->getOperand(1), ElementIndex,
+ Elements, VecEltTy);
+ case Instruction::Shl: {
+ // Must be shifting by a constant that is a multiple of the element size.
+ ConstantInt *CI = dyn_cast<ConstantInt>(I->getOperand(1));
+ if (CI == 0) return false;
+ if (!isMultipleOfTypeSize(CI->getZExtValue(), VecEltTy)) return false;
+ unsigned IndexShift = getTypeSizeIndex(CI->getZExtValue(), VecEltTy);
+
+ return CollectInsertionElements(I->getOperand(0), ElementIndex+IndexShift,
+ Elements, VecEltTy);
+ }
+
+ }
+}
+
+
+/// OptimizeIntegerToVectorInsertions - If the input is an 'or' instruction, we
+/// may be doing shifts and ors to assemble the elements of the vector manually.
+/// Try to rip the code out and replace it with insertelements. This is to
+/// optimize code like this:
+///
+/// %tmp37 = bitcast float %inc to i32
+/// %tmp38 = zext i32 %tmp37 to i64
+/// %tmp31 = bitcast float %inc5 to i32
+/// %tmp32 = zext i32 %tmp31 to i64
+/// %tmp33 = shl i64 %tmp32, 32
+/// %ins35 = or i64 %tmp33, %tmp38
+/// %tmp43 = bitcast i64 %ins35 to <2 x float>
+///
+/// Into two insertelements that do "buildvector{%inc, %inc5}".
+static Value *OptimizeIntegerToVectorInsertions(BitCastInst &CI,
+ InstCombiner &IC) {
+ const VectorType *DestVecTy = cast<VectorType>(CI.getType());
+ Value *IntInput = CI.getOperand(0);
+
+ SmallVector<Value*, 8> Elements(DestVecTy->getNumElements());
+ if (!CollectInsertionElements(IntInput, 0, Elements,
+ DestVecTy->getElementType()))
+ return 0;
+
+ // If we succeeded, we know that all of the element are specified by Elements
+ // or are zero if Elements has a null entry. Recast this as a set of
+ // insertions.
+ Value *Result = Constant::getNullValue(CI.getType());
+ for (unsigned i = 0, e = Elements.size(); i != e; ++i) {
+ if (Elements[i] == 0) continue; // Unset element.
+
+ Result = IC.Builder->CreateInsertElement(Result, Elements[i],
+ IC.Builder->getInt32(i));
+ }
+
+ return Result;
+}
+
+
/// OptimizeIntToFloatBitCast - See if we can optimize an integer->float/double
/// bitcast. The various long double bitcasts can't get in here.
static Instruction *OptimizeIntToFloatBitCast(BitCastInst &CI,InstCombiner &IC){
@@ -1478,16 +1588,24 @@
// FIXME: Canonicalize bitcast(insertelement) -> insertelement(bitcast)
}
- // If this is a cast from an integer to vector, check to see if the input
- // is a trunc or zext of a bitcast from vector. If so, we can replace all
- // the casts with a shuffle and (potentially) a bitcast.
- if (isa<IntegerType>(SrcTy) && (isa<TruncInst>(Src) || isa<ZExtInst>(Src))){
- CastInst *SrcCast = cast<CastInst>(Src);
- if (BitCastInst *BCIn = dyn_cast<BitCastInst>(SrcCast->getOperand(0)))
- if (isa<VectorType>(BCIn->getOperand(0)->getType()))
- if (Instruction *I = OptimizeVectorResize(BCIn->getOperand(0),
+ if (isa<IntegerType>(SrcTy)) {
+ // If this is a cast from an integer to vector, check to see if the input
+ // is a trunc or zext of a bitcast from vector. If so, we can replace all
+ // the casts with a shuffle and (potentially) a bitcast.
+ if (isa<TruncInst>(Src) || isa<ZExtInst>(Src)) {
+ CastInst *SrcCast = cast<CastInst>(Src);
+ if (BitCastInst *BCIn = dyn_cast<BitCastInst>(SrcCast->getOperand(0)))
+ if (isa<VectorType>(BCIn->getOperand(0)->getType()))
+ if (Instruction *I = OptimizeVectorResize(BCIn->getOperand(0),
cast<VectorType>(DestTy), *this))
- return I;
+ return I;
+ }
+
+ // If the input is an 'or' instruction, we may be doing shifts and ors to
+ // assemble the elements of the vector manually. Try to rip the code out
+ // and replace it with insertelements.
+ if (Value *V = OptimizeIntegerToVectorInsertions(CI, *this))
+ return ReplaceInstUsesWith(CI, V);
}
}
Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineShifts.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineShifts.cpp?rev=112343&r1=112342&r2=112343&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineShifts.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineShifts.cpp Fri Aug 27 20:20:38 2010
@@ -312,8 +312,8 @@
// cast of lshr(shl(x,c1),c2) as well as other more complex cases.
if (I.getOpcode() != Instruction::AShr &&
CanEvaluateShifted(Op0, Op1->getZExtValue(), isLeftShift, *this)) {
- DEBUG(dbgs() << "ICE: GetShiftedValue propagatin shift through expression"
- " to eliminate shift:\n IN: " << *Op0 << "\nSH: " << I << "\n");
+ DEBUG(dbgs() << "ICE: GetShiftedValue propagating shift through expression"
+ " to eliminate shift:\n IN: " << *Op0 << "\n SH: " << I <<"\n");
return ReplaceInstUsesWith(I,
GetShiftedValue(Op0, Op1->getZExtValue(), isLeftShift, *this));
Modified: llvm/trunk/test/Transforms/InstCombine/bitcast.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/bitcast.ll?rev=112343&r1=112342&r2=112343&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/bitcast.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/bitcast.ll Fri Aug 27 20:20:38 2010
@@ -60,3 +60,34 @@
; CHECK-NEXT: %add = fadd float %tmp24, %tmp4
; CHECK-NEXT: ret float %add
}
+
+
+define <2 x i32> @test4(i32 %A, i32 %B){
+ %tmp38 = zext i32 %A to i64
+ %tmp32 = zext i32 %B to i64
+ %tmp33 = shl i64 %tmp32, 32
+ %ins35 = or i64 %tmp33, %tmp38
+ %tmp43 = bitcast i64 %ins35 to <2 x i32>
+ ret <2 x i32> %tmp43
+ ; CHECK: @test4
+ ; CHECK-NEXT: insertelement <2 x i32> undef, i32 %A, i32 0
+ ; CHECK-NEXT: insertelement <2 x i32> {{.*}}, i32 %B, i32 1
+ ; CHECK-NEXT: ret <2 x i32>
+
+}
+
+; rdar://8360454
+define <2 x float> @test5(float %A, float %B) {
+ %tmp37 = bitcast float %A to i32
+ %tmp38 = zext i32 %tmp37 to i64
+ %tmp31 = bitcast float %B to i32
+ %tmp32 = zext i32 %tmp31 to i64
+ %tmp33 = shl i64 %tmp32, 32
+ %ins35 = or i64 %tmp33, %tmp38
+ %tmp43 = bitcast i64 %ins35 to <2 x float>
+ ret <2 x float> %tmp43
+ ; CHECK: @test5
+ ; CHECK-NEXT: insertelement <2 x float> undef, float %A, i32 0
+ ; CHECK-NEXT: insertelement <2 x float> {{.*}}, float %B, i32 1
+ ; CHECK-NEXT: ret <2 x float>
+}
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