; NOTE: Assertions have been autogenerated by utils/update_test_checks.py ; RUN: opt < %s -passes=instcombine -S | FileCheck %s ; Verify that an excessive size to strncmp() isn't truncated to an in-bounds ; value that results in the call being incorrectly folded (as might happen ; when LLVM is compiled in ILP32 mode). declare i32 @strncmp(i8*, i8*, i64) @ax = external global [0 x i8] @bx = external global [0 x i8] @a12345 = constant [5 x i8] c"\01\02\03\04\05" @a123456 = constant [6 x i8] c"\01\02\03\04\05\06" ; Do not fold strncmp(ax, bx, UINT_MAX + (size_t)1) to 0. define i32 @call_strncmp_ax_bx_uimax_p1() { ; CHECK-LABEL: @call_strncmp_ax_bx_uimax_p1( ; CHECK-NEXT: [[RES:%.*]] = call i32 @strncmp(i8* noundef nonnull dereferenceable(1) getelementptr inbounds ([0 x i8], [0 x i8]* @ax, i64 0, i64 0), i8* noundef nonnull dereferenceable(1) getelementptr inbounds ([0 x i8], [0 x i8]* @bx, i64 0, i64 0), i64 4294967296) ; CHECK-NEXT: ret i32 [[RES]] ; %p1 = getelementptr [0 x i8], [0 x i8]* @ax, i32 0, i32 0 %p2 = getelementptr [0 x i8], [0 x i8]* @bx, i32 0, i32 0 %res = call i32 @strncmp(i8* %p1, i8* %p2, i64 4294967296) ret i32 %res } ; Do not fold strncmp(ax, bx, UINT_MAX + (size_t)2) to *ax - *bx. define i32 @call_strncmp_ax_bx_uimax_p2() { ; CHECK-LABEL: @call_strncmp_ax_bx_uimax_p2( ; CHECK-NEXT: [[RES:%.*]] = call i32 @strncmp(i8* noundef nonnull dereferenceable(1) getelementptr inbounds ([0 x i8], [0 x i8]* @ax, i64 0, i64 0), i8* noundef nonnull dereferenceable(1) getelementptr inbounds ([0 x i8], [0 x i8]* @bx, i64 0, i64 0), i64 4294967296) ; CHECK-NEXT: ret i32 [[RES]] ; %p1 = getelementptr [0 x i8], [0 x i8]* @ax, i32 0, i32 0 %p2 = getelementptr [0 x i8], [0 x i8]* @bx, i32 0, i32 0 %res = call i32 @strncmp(i8* %p1, i8* %p2, i64 4294967296) ret i32 %res } ; Fold strncmp(a12345, a123456, UINT_MAX + (size_t)2) to -1 (and not to 0). define i32 @fold_strncmp_a12345_2_uimax_p2() { ; CHECK-LABEL: @fold_strncmp_a12345_2_uimax_p2( ; CHECK-NEXT: ret i32 -1 ; %p1 = getelementptr [5 x i8], [5 x i8]* @a12345, i32 0, i32 0 %p2 = getelementptr [6 x i8], [6 x i8]* @a123456, i32 0, i32 0 %res = call i32 @strncmp(i8* %p1, i8* %p2, i64 4294967297) ret i32 %res } ; Fold strncmp(a123456, a12345, UINT_MAX + (size_t)3) to +1 (and not to 0). define i32 @fold_strncmp_a12345_2_uimax_p3() { ; CHECK-LABEL: @fold_strncmp_a12345_2_uimax_p3( ; CHECK-NEXT: ret i32 1 ; %p1 = getelementptr [6 x i8], [6 x i8]* @a123456, i32 0, i32 0 %p2 = getelementptr [5 x i8], [5 x i8]* @a12345, i32 0, i32 0 %res = call i32 @strncmp(i8* %p1, i8* %p2, i64 4294967298) ret i32 %res }