[llvm] 843c0ad - [ConstantFold] Fold extractelement of getelementptr
Jay Foad via llvm-commits
llvm-commits at lists.llvm.org
Mon Oct 28 11:32:54 PDT 2019
Author: Jay Foad
Date: 2019-10-28T18:32:39Z
New Revision: 843c0adf0f7449a4167d20b399f70f6943d21d5e
URL: https://github.com/llvm/llvm-project/commit/843c0adf0f7449a4167d20b399f70f6943d21d5e
DIFF: https://github.com/llvm/llvm-project/commit/843c0adf0f7449a4167d20b399f70f6943d21d5e.diff
LOG: [ConstantFold] Fold extractelement of getelementptr
Summary:
Getelementptr has vector type if any of its operands are vectors
(the scalar operands being implicitly broadcast to all vector elements).
Extractelement applied to a vector getelementptr can be folded by
applying the extractelement in turn to all of the vector operands.
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D69379
Added:
Modified:
llvm/lib/IR/ConstantFold.cpp
llvm/test/Analysis/ConstantFolding/gep-zeroinit-vector.ll
llvm/test/Transforms/InstCombine/vec_demanded_elts.ll
llvm/test/Transforms/LoopVectorize/X86/constant-fold.ll
Removed:
################################################################################
diff --git a/llvm/lib/IR/ConstantFold.cpp b/llvm/lib/IR/ConstantFold.cpp
index 71fa795ec294..84b117de21e6 100644
--- a/llvm/lib/IR/ConstantFold.cpp
+++ b/llvm/lib/IR/ConstantFold.cpp
@@ -792,13 +792,36 @@ Constant *llvm::ConstantFoldExtractElementInstruction(Constant *Val,
if (isa<UndefValue>(Val) || isa<UndefValue>(Idx))
return UndefValue::get(Val->getType()->getVectorElementType());
- if (ConstantInt *CIdx = dyn_cast<ConstantInt>(Idx)) {
- // ee({w,x,y,z}, wrong_value) -> undef
- if (CIdx->uge(Val->getType()->getVectorNumElements()))
- return UndefValue::get(Val->getType()->getVectorElementType());
- return Val->getAggregateElement(CIdx->getZExtValue());
+ auto *CIdx = dyn_cast<ConstantInt>(Idx);
+ if (!CIdx)
+ return nullptr;
+
+ // ee({w,x,y,z}, wrong_value) -> undef
+ if (CIdx->uge(Val->getType()->getVectorNumElements()))
+ return UndefValue::get(Val->getType()->getVectorElementType());
+
+ // ee (gep (ptr, idx0, ...), idx) -> gep (ee (ptr, idx), ee (idx0, idx), ...)
+ if (auto *CE = dyn_cast<ConstantExpr>(Val)) {
+ if (CE->getOpcode() == Instruction::GetElementPtr) {
+ SmallVector<Constant *, 8> Ops;
+ Ops.reserve(CE->getNumOperands());
+ for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
+ Constant *Op = CE->getOperand(i);
+ if (Op->getType()->isVectorTy()) {
+ Constant *ScalarOp = ConstantFoldExtractElementInstruction(Op, Idx);
+ if (!ScalarOp)
+ return nullptr;
+ Ops.push_back(ScalarOp);
+ } else
+ Ops.push_back(Op);
+ }
+ return CE->getWithOperands(Ops, CE->getType()->getVectorElementType(),
+ false,
+ Ops[0]->getType()->getPointerElementType());
+ }
}
- return nullptr;
+
+ return Val->getAggregateElement(CIdx);
}
Constant *llvm::ConstantFoldInsertElementInstruction(Constant *Val,
diff --git a/llvm/test/Analysis/ConstantFolding/gep-zeroinit-vector.ll b/llvm/test/Analysis/ConstantFolding/gep-zeroinit-vector.ll
index bb5fcbdb8ba5..03d27e9fb6c5 100644
--- a/llvm/test/Analysis/ConstantFolding/gep-zeroinit-vector.ll
+++ b/llvm/test/Analysis/ConstantFolding/gep-zeroinit-vector.ll
@@ -9,7 +9,7 @@
define <2 x i16*> @test_gep() {
; CHECK-LABEL: @test_gep(
-; CHECK-NEXT: ret <2 x i16*> <i16* getelementptr inbounds (%rec8, %rec8* extractelement (<2 x %rec8*> getelementptr ([1 x %rec8], [1 x %rec8]* @a, <2 x i64> zeroinitializer, <2 x i64> zeroinitializer), i32 0), i32 0, i32 0), i16* getelementptr inbounds (%rec8, %rec8* extractelement (<2 x %rec8*> getelementptr ([1 x %rec8], [1 x %rec8]* @a, <2 x i64> zeroinitializer, <2 x i64> zeroinitializer), i32 1), i32 0, i32 0)>
+; CHECK-NEXT: ret <2 x i16*> <i16* getelementptr inbounds ([1 x %rec8], [1 x %rec8]* @a, i32 0, i32 0, i32 0), i16* getelementptr inbounds ([1 x %rec8], [1 x %rec8]* @a, i32 0, i32 0, i32 0)>
;
%A = getelementptr [1 x %rec8], [1 x %rec8]* @a, <2 x i16> zeroinitializer, <2 x i64> zeroinitializer
%B = bitcast <2 x %rec8*> %A to <2 x i16*>
diff --git a/llvm/test/Transforms/InstCombine/vec_demanded_elts.ll b/llvm/test/Transforms/InstCombine/vec_demanded_elts.ll
index 164061de5112..0c3f60861430 100644
--- a/llvm/test/Transforms/InstCombine/vec_demanded_elts.ll
+++ b/llvm/test/Transforms/InstCombine/vec_demanded_elts.ll
@@ -569,7 +569,7 @@ define i32* @gep_cvbase_w_s_idx(<2 x i32*> %base, i64 %raw_addr) {
define i32* @gep_cvbase_w_cv_idx(<2 x i32*> %base, i64 %raw_addr) {
; CHECK-LABEL: @gep_cvbase_w_cv_idx(
-; CHECK-NEXT: ret i32* extractelement (<2 x i32*> getelementptr (i32, <2 x i32*> <i32* @GLOBAL, i32* @GLOBAL>, <2 x i64> <i64 0, i64 1>), i32 1)
+; CHECK-NEXT: ret i32* getelementptr inbounds (i32, i32* @GLOBAL, i64 1)
;
%gep = getelementptr i32, <2 x i32*> <i32* @GLOBAL, i32* @GLOBAL>, <2 x i64> <i64 0, i64 1>
%ee = extractelement <2 x i32*> %gep, i32 1
diff --git a/llvm/test/Transforms/LoopVectorize/X86/constant-fold.ll b/llvm/test/Transforms/LoopVectorize/X86/constant-fold.ll
index a73d91ba30b7..360a52c619bc 100644
--- a/llvm/test/Transforms/LoopVectorize/X86/constant-fold.ll
+++ b/llvm/test/Transforms/LoopVectorize/X86/constant-fold.ll
@@ -27,7 +27,7 @@ define void @f1() {
; CHECK-NEXT: [[TMP2:%.*]] = getelementptr [2 x i16*], [2 x i16*]* @b, i16 0, i64 [[TMP1]]
; CHECK-NEXT: [[TMP3:%.*]] = getelementptr i16*, i16** [[TMP2]], i32 0
; CHECK-NEXT: [[TMP4:%.*]] = bitcast i16** [[TMP3]] to <2 x i16*>*
-; CHECK-NEXT: store <2 x i16*> <i16* getelementptr inbounds (%rec8, %rec8* extractelement (<2 x %rec8*> getelementptr ([1 x %rec8], [1 x %rec8]* @a, <2 x i16> zeroinitializer, <2 x i64> zeroinitializer), i32 0), i32 0, i32 0), i16* getelementptr inbounds (%rec8, %rec8* extractelement (<2 x %rec8*> getelementptr ([1 x %rec8], [1 x %rec8]* @a, <2 x i16> zeroinitializer, <2 x i64> zeroinitializer), i32 1), i32 0, i32 0)>, <2 x i16*>* [[TMP4]], align 8
+; CHECK-NEXT: store <2 x i16*> <i16* getelementptr inbounds ([1 x %rec8], [1 x %rec8]* @a, i32 0, i32 0, i32 0), i16* getelementptr inbounds ([1 x %rec8], [1 x %rec8]* @a, i32 0, i32 0, i32 0)>, <2 x i16*>* [[TMP4]], align 8
; CHECK-NEXT: [[INDEX_NEXT]] = add i32 [[INDEX]], 2
; CHECK-NEXT: [[TMP5:%.*]] = icmp eq i32 [[INDEX_NEXT]], 2
; CHECK-NEXT: br i1 [[TMP5]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop !0
More information about the llvm-commits
mailing list