}
// In addition to the cases handle just above, we need to prevent
- // allocas from moving below a stacksave. The stackrestore case
- // is currently thought to be conservatism.
- if (isa<AllocaInst>(BundleMember->Inst)) {
+ // allocas and loads/stores from moving below a stacksave or a
+ // stackrestore. Avoiding moving allocas below stackrestore is currently
+ // thought to be conservatism. Moving loads/stores below a stackrestore
+ // can lead to incorrect code.
+ if (isa<AllocaInst>(BundleMember->Inst) ||
+ BundleMember->Inst->mayReadOrWriteMemory()) {
for (Instruction *I = BundleMember->Inst->getNextNode();
I != ScheduleEnd; I = I->getNextNode()) {
if (!match(I, m_Intrinsic<Intrinsic::stacksave>()) &&
--- /dev/null
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -passes=slp-vectorizer -slp-threshold=-999 -mtriple=x86_64-unknown-linux-gnu -mcpu=skylake -S < %s | FileCheck %s
+
+; The test checks that loads should not be moved below a stackrestore boundary.
+define void @stackrestore1(ptr %out) {
+; CHECK-LABEL: @stackrestore1(
+; CHECK-NEXT: [[STACK:%.*]] = call ptr @llvm.stacksave()
+; CHECK-NEXT: [[LOCAL_ALLOCA:%.*]] = alloca [16 x i8], align 4
+; CHECK-NEXT: store <4 x float> <float 0x3FF3333340000000, float 0x3FF3333340000000, float 0x3FF3333340000000, float 0x3FF3333340000000>, ptr [[LOCAL_ALLOCA]], align 4
+; CHECK-NEXT: [[TMP1:%.*]] = load <4 x float>, ptr [[LOCAL_ALLOCA]], align 4
+; CHECK-NEXT: call void @llvm.stackrestore(ptr [[STACK]])
+; CHECK-NEXT: [[SHUFFLE:%.*]] = shufflevector <4 x float> [[TMP1]], <4 x float> poison, <4 x i32> <i32 2, i32 3, i32 0, i32 1>
+; CHECK-NEXT: store <4 x float> [[SHUFFLE]], ptr [[OUT:%.*]], align 4
+; CHECK-NEXT: ret void
+;
+ %stack = call ptr @llvm.stacksave()
+ %local_alloca = alloca [16 x i8], align 4
+ store float 0x3FF3333340000000, ptr %local_alloca, align 4
+ %addr1 = getelementptr inbounds i8, ptr %local_alloca, i64 4
+ store float 0x3FF3333340000000, ptr %addr1, align 4
+ %addr2 = getelementptr inbounds i8, ptr %local_alloca, i64 8
+ store float 0x3FF3333340000000, ptr %addr2, align 4
+ %addr3 = getelementptr inbounds i8, ptr %local_alloca, i64 12
+ store float 0x3FF3333340000000, ptr %addr3, align 4
+ %val0 = load float, ptr %local_alloca, align 4
+ %val1 = load float, ptr %addr1, align 4
+ %val2 = load float, ptr %addr2, align 4
+ %val3 = load float, ptr %addr3, align 4
+ call void @llvm.stackrestore(i8* %stack)
+ %outaddr2 = getelementptr inbounds float, ptr %out, i64 2
+ store float %val0, ptr %outaddr2, align 4
+ %outaddr3 = getelementptr inbounds float, ptr %out, i64 3
+ store float %val1, ptr %outaddr3, align 4
+ store float %val2, ptr %out
+ %outaddr1 = getelementptr inbounds float, ptr %out, i64 1
+ store float %val3, ptr %outaddr1, align 4
+ ret void
+}
+
+declare i8* @llvm.stacksave()
+declare void @llvm.stackrestore(i8*)