| ; RUN: opt -S -basic-aa -gvn < %s | FileCheck %s |
| ; RUN: opt -S -basic-aa -gvn -disable-simplify-libcalls < %s | FileCheck %s -check-prefix=CHECK_NO_LIBCALLS |
| ; Check that loads from calloc are recognized as being zero. |
| |
| 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" |
| |
| ; Function Attrs: nounwind uwtable |
| define i32 @test1() { |
| %1 = tail call noalias i8* @calloc(i64 1, i64 4) |
| %2 = bitcast i8* %1 to i32* |
| ; This load is trivially constant zero |
| %3 = load i32, i32* %2, align 4 |
| ret i32 %3 |
| |
| ; CHECK-LABEL: @test1( |
| ; CHECK-NOT: %3 = load i32, i32* %2, align 4 |
| ; CHECK: ret i32 0 |
| |
| ; CHECK_NO_LIBCALLS-LABEL: @test1( |
| ; CHECK_NO_LIBCALLS: load |
| ; CHECK_NO_LIBCALLS: ret i32 % |
| |
| } |
| |
| declare noalias i8* @calloc(i64, i64) |
