1; RUN: opt -S -basicaa -gvn < %s | FileCheck %s 2; RUN: opt -S -basicaa -gvn -disable-simplify-libcalls < %s | FileCheck %s -check-prefix=CHECK_NO_LIBCALLS 3; Check that loads from calloc are recognized as being zero. 4 5target 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" 6 7; Function Attrs: nounwind uwtable 8define i32 @test1() { 9 %1 = tail call noalias i8* @calloc(i64 1, i64 4) 10 %2 = bitcast i8* %1 to i32* 11 ; This load is trivially constant zero 12 %3 = load i32, i32* %2, align 4 13 ret i32 %3 14 15; CHECK-LABEL: @test1( 16; CHECK-NOT: %3 = load i32, i32* %2, align 4 17; CHECK: ret i32 0 18 19; CHECK_NO_LIBCALLS-LABEL: @test1( 20; CHECK_NO_LIBCALLS: load 21; CHECK_NO_LIBCALLS: ret i32 % 22 23} 24 25declare noalias i8* @calloc(i64, i64) 26