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82ee16beb8
C requires the operands of arithmetic expressions to be promoted if their types are smaller than an int. Ubsan emits overflow checks when this sort of type promotion occurs, even if there is no way to actually get an overflow with the promoted type. This patch teaches clang how to omit the superflous overflow checks (addressing PR20193). Testing: check-clang and check-ubsan. Differential Revision: https://reviews.llvm.org/D29369 llvm-svn: 296213
31 lines
1.3 KiB
C
31 lines
1.3 KiB
C
// Check -fsanitize=signed-integer-overflow and
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// -fsanitize=unsigned-integer-overflow with promoted unsigned types
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//
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// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -emit-llvm -o - %s \
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// RUN: -fsanitize=signed-integer-overflow | FileCheck %s --check-prefix=CHECKS
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// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -emit-llvm -o - %s \
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// RUN: -fsanitize=unsigned-integer-overflow | FileCheck %s --check-prefix=CHECKU
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unsigned short si, sj, sk;
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// CHECKS-LABEL: define void @testshortmul()
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// CHECKU-LABEL: define void @testshortmul()
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void testshortmul() {
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// CHECKS: load i16, i16* @sj
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// CHECKS: load i16, i16* @sk
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// CHECKS: [[T1:%.*]] = call { i32, i1 } @llvm.smul.with.overflow.i32(i32 [[T2:%.*]], i32 [[T3:%.*]])
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// CHECKS-NEXT: [[T4:%.*]] = extractvalue { i32, i1 } [[T1]], 0
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// CHECKS-NEXT: [[T5:%.*]] = extractvalue { i32, i1 } [[T1]], 1
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// CHECKS: call void @__ubsan_handle_mul_overflow
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//
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// CHECKU: [[T1:%.*]] = load i16, i16* @sj
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// CHECKU: [[T2:%.*]] = zext i16 [[T1]]
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// CHECKU: [[T3:%.*]] = load i16, i16* @sk
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// CHECKU: [[T4:%.*]] = zext i16 [[T3]]
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// CHECKU-NOT: llvm.smul
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// CHECKU-NOT: llvm.umul
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// CHECKU: [[T5:%.*]] = mul nsw i32 [[T2]], [[T4]]
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si = sj * sk;
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}
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