; NOTE: Assertions have been autogenerated by utils/update_test_checks.py ; Verify that calls to memcmp with counts in excess of the array sizes are ; either folded gracefully or expanded to library calls. ; ; RUN: opt < %s -passes=instcombine -S -data-layout="E" | FileCheck %s --check-prefixes=BE ; RUN: opt < %s -passes=instcombine -S -data-layout="e" | FileCheck %s --check-prefixes=LE declare i32 @memcmp(i8*, i8*, i64) @ia16a = constant [4 x i16] [i16 24930, i16 25444, i16 25958, i16 26472] @ia16b = constant [5 x i16] [i16 24930, i16 25444, i16 25958, i16 26472, i16 26992] @ia16c = constant [6 x i16] [i16 24930, i16 25444, i16 25958, i16 26472, i16 26993, i16 29042] ; Fold calls with a count in excess of the size of one of the arrays that ; differ. They're strictly undefined but folding the result to the expected ; value (analogous to strncmp) is safer than letting a SIMD library ; implementation return a bogus value. define void @fold_memcmp_mismatch_too_big(i32* %pcmp) { ; BE-LABEL: @fold_memcmp_mismatch_too_big( ; BE-NEXT: store i32 -1, i32* [[PCMP:%.*]], align 4 ; BE-NEXT: [[PSTOR_CB:%.*]] = getelementptr i32, i32* [[PCMP]], i64 1 ; BE-NEXT: store i32 1, i32* [[PSTOR_CB]], align 4 ; BE-NEXT: ret void ; ; LE-LABEL: @fold_memcmp_mismatch_too_big( ; LE-NEXT: store i32 -1, i32* [[PCMP:%.*]], align 4 ; LE-NEXT: [[PSTOR_CB:%.*]] = getelementptr i32, i32* [[PCMP]], i64 1 ; LE-NEXT: store i32 1, i32* [[PSTOR_CB]], align 4 ; LE-NEXT: ret void ; %p0 = getelementptr [5 x i16], [5 x i16]* @ia16b, i64 0, i64 0 %p1 = bitcast i16* %p0 to i8* %q0 = getelementptr [6 x i16], [6 x i16]* @ia16c, i64 0, i64 0 %q1 = bitcast i16* %q0 to i8* %cmp_bc = call i32 @memcmp(i8* %p1, i8* %q1, i64 12) %pstor_bc = getelementptr i32, i32* %pcmp, i64 0 store i32 %cmp_bc, i32* %pstor_bc %cmp_cb = call i32 @memcmp(i8* %q1, i8* %p1, i64 12) %pstor_cb = getelementptr i32, i32* %pcmp, i64 1 store i32 %cmp_cb, i32* %pstor_cb ret void } ; Fold even calls with excessive byte counts of arrays with matching bytes. ; Like in the instances above, this is preferable to letting the undefined ; calls take place, although it does prevent sanitizers from detecting them. define void @fold_memcmp_match_too_big(i32* %pcmp) { ; BE-LABEL: @fold_memcmp_match_too_big( ; BE-NEXT: store i32 0, i32* [[PCMP:%.*]], align 4 ; BE-NEXT: [[PSTOR_AB_M1:%.*]] = getelementptr i32, i32* [[PCMP]], i64 1 ; BE-NEXT: store i32 0, i32* [[PSTOR_AB_M1]], align 4 ; BE-NEXT: ret void ; ; LE-LABEL: @fold_memcmp_match_too_big( ; LE-NEXT: store i32 0, i32* [[PCMP:%.*]], align 4 ; LE-NEXT: [[PSTOR_AB_M1:%.*]] = getelementptr i32, i32* [[PCMP]], i64 1 ; LE-NEXT: store i32 0, i32* [[PSTOR_AB_M1]], align 4 ; LE-NEXT: ret void ; %p0 = getelementptr [4 x i16], [4 x i16]* @ia16a, i64 0, i64 0 %p1 = bitcast i16* %p0 to i8* %q0 = getelementptr [5 x i16], [5 x i16]* @ia16b, i64 0, i64 0 %q1 = bitcast i16* %q0 to i8* %cmp_ab_9 = call i32 @memcmp(i8* %p1, i8* %q1, i64 9) %pstor_ab_9 = getelementptr i32, i32* %pcmp, i64 0 store i32 %cmp_ab_9, i32* %pstor_ab_9 %cmp_ab_m1 = call i32 @memcmp(i8* %p1, i8* %q1, i64 -1) %pstor_ab_m1 = getelementptr i32, i32* %pcmp, i64 1 store i32 %cmp_ab_m1, i32* %pstor_ab_m1 ret void }