--- /dev/null
+; RUN: opt -S -instcombine < %s | FileCheck %s
+target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128-n8:16:32"
+target triple = "i386-apple-darwin10.0.0"
+
+define void @fu1(i32 %parm) nounwind ssp {
+ %1 = alloca i32, align 4
+ %ptr = alloca double*, align 4
+ store i32 %parm, i32* %1, align 4
+ store double* null, double** %ptr, align 4
+ %2 = load i32* %1, align 4
+ %3 = icmp ne i32 %2, 0
+ br i1 %3, label %4, label %10
+
+; <label>:4 ; preds = %0
+ %5 = load i32* %1, align 4
+ %6 = mul nsw i32 %5, 8
+; With "nsw", the alloca and its bitcast can be fused:
+ %7 = add nsw i32 %6, 2048
+; CHECK: alloca double*
+ %8 = alloca i8, i32 %7
+ %9 = bitcast i8* %8 to double*
+ store double* %9, double** %ptr, align 4
+ br label %10
+
+; <label>:10 ; preds = %4, %0
+ %11 = load double** %ptr, align 4
+ call void @bar(double* %11)
+; CHECK: ret
+ ret void
+}
+
+declare void @bar(double*)
+
+define void @fu2(i32 %parm) nounwind ssp {
+ %1 = alloca i32, align 4
+ %ptr = alloca double*, align 4
+ store i32 %parm, i32* %1, align 4
+ store double* null, double** %ptr, align 4
+ %2 = load i32* %1, align 4
+ %3 = icmp ne i32 %2, 0
+ br i1 %3, label %4, label %10
+
+; <label>:4 ; preds = %0
+ %5 = load i32* %1, align 4
+ %6 = mul nsw i32 %5, 8
+; Without "nsw", the alloca and its bitcast cannot be fused:
+ %7 = add i32 %6, 2048
+; CHECK: alloca i8
+ %8 = alloca i8, i32 %7
+; CHECK-NEXT: bitcast i8*
+ %9 = bitcast i8* %8 to double*
+ store double* %9, double** %ptr, align 4
+ br label %10
+
+; <label>:10 ; preds = %4, %0
+ %11 = load double** %ptr, align 4
+ call void @bar(double* %11)
+ ret void
+}
+