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