STATISTIC(NumDeadStore, "Number of dead stores eliminated");
Instruction *InstCombiner::visitAllocaInst(AllocaInst &AI) {
+ // Ensure that the alloca array size argument has type intptr_t, so that
+ // any casting is exposed early.
+ if (TD) {
+ const Type *IntPtrTy = TD->getIntPtrType(AI.getContext());
+ if (AI.getArraySize()->getType() != IntPtrTy) {
+ Value *V = Builder->CreateIntCast(AI.getArraySize(),
+ IntPtrTy, false);
+ AI.setOperand(0, V);
+ return &AI;
+ }
+ }
+
// Convert: alloca Ty, C - where C is a constant != 1 into: alloca [C x Ty], 1
if (AI.isArrayAllocation()) { // Check C != 1
if (const ConstantInt *C = dyn_cast<ConstantInt>(AI.getArraySize())) {
-; Zero byte allocas should be deleted.
target datalayout = "E-p:64:64:64-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-v64:64:64-v128:128:128"
-; RUN: opt < %s -instcombine -S | \
-; RUN: not grep alloca
+; RUN: opt < %s -instcombine -S | FileCheck %s
; END.
declare void @use(...)
+; Zero byte allocas should be deleted.
+; CHECK: @test
+; CHECK-NOT: alloca
define void @test() {
%X = alloca [0 x i32] ; <[0 x i32]*> [#uses=1]
call void (...)* @use( [0 x i32]* %X )
ret void
}
+; Zero byte allocas should be deleted.
+; CHECK: @test2
+; CHECK-NOT: alloca
define void @test2() {
%A = alloca i32 ; <i32*> [#uses=1]
store i32 123, i32* %A
ret void
}
+; Zero byte allocas should be deleted.
+; CHECK: @test3
+; CHECK-NOT: alloca
define void @test3() {
%A = alloca { i32 } ; <{ i32 }*> [#uses=1]
%B = getelementptr { i32 }* %A, i32 0, i32 0 ; <i32*> [#uses=1]
ret void
}
+; CHECK: @test4
+; CHECK: = zext i32 %n to i64
+; CHECK: %A = alloca i32, i64 %
+define i32* @test4(i32 %n) {
+ %A = alloca i32, i32 %n
+ ret i32* %A
+}