// See if instruction simplification can hack this up. This is common for
// things like "select false, X, Y" after unswitching made the condition be
- // 'false'.
- if (Value *V = SimplifyInstruction(I, 0, 0, DT))
+ // 'false'. TODO: update the domtree properly so we can pass it here.
+ if (Value *V = SimplifyInstruction(I))
if (LI->replacementPreservesLCSSAForm(I, V)) {
ReplaceUsesOfWith(I, V, Worklist, L, LPM);
continue;
--- /dev/null
+; RUN: opt < %s -loop-unswitch -disable-output
+; PR12887
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+@a = common global i32 0, align 4
+@c = common global i32 0, align 4
+@b = common global i32 0, align 4
+
+define void @func() noreturn nounwind uwtable {
+entry:
+ %0 = load i32* @a, align 4
+ %tobool = icmp eq i32 %0, 0
+ %1 = load i32* @b, align 4
+ br label %while.body
+
+while.body: ; preds = %while.body, %entry
+ %d.0 = phi i8 [ undef, %entry ], [ %conv2, %while.body ]
+ %conv = sext i8 %d.0 to i32
+ %cond = select i1 %tobool, i32 0, i32 %conv
+ %conv11 = zext i8 %d.0 to i32
+ %add = add i32 %1, %conv11
+ %conv2 = trunc i32 %add to i8
+ br label %while.body
+}