Summary:
This fixes PR45885 by fixing isGuaranteedNotToBeUndefOrPoison so it does not look into dominating
branch conditions of V when V is an instruction in an unreachable block.
Reviewers: spatel, nikic, lebedev.ri
Reviewed By: nikic
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D79790
if (!CtxI || !CtxI->getParent() || !DT)
return false;
+ auto *DNode = DT->getNode(CtxI->getParent());
+ if (!DNode)
+ // Unreachable block
+ return false;
+
// If V is used as a branch condition before reaching CtxI, V cannot be
// undef or poison.
// br V, BB1, BB2
// BB1:
// CtxI ; V cannot be undef or poison here
- auto Dominator = DT->getNode(CtxI->getParent())->getIDom();
+ auto *Dominator = DNode->getIDom();
while (Dominator) {
auto *TI = Dominator->getBlock()->getTerminator();
--- /dev/null
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -div-rem-pairs -S -mtriple=powerpc64-unknown-unknown | FileCheck %s
+
+define void @g() {
+; CHECK-LABEL: @g(
+; CHECK-NEXT: if.end:
+; CHECK-NEXT: ret void
+; CHECK: for.cond:
+; CHECK-NEXT: [[TMP0:%.*]] = mul i16 [[DIV_I:%.*]], [[REM_FROZEN:%.*]]
+; CHECK-NEXT: [[REM_DECOMPOSED:%.*]] = sub i16 1, [[TMP0]]
+; CHECK-NEXT: [[REM_FROZEN]] = freeze i16 [[REM_DECOMPOSED]]
+; CHECK-NEXT: [[DIV_I]] = sdiv i16 1, [[REM_FROZEN]]
+; CHECK-NEXT: br label [[FOR_COND:%.*]]
+;
+if.end:
+ ret void
+
+for.cond: ; preds = %for.cond
+ %rem = srem i16 1, %rem
+ %div.i = sdiv i16 1, %rem
+ br label %for.cond
+}
+
+