| 1 | // RUN: %clang_cc1 -S %s -emit-llvm -o - | FileCheck %s |
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| 2 | // RUN: %clang_cc1 -S %s -emit-llvm -triple i686-unknown-unknown -o - | FileCheck %s |
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| 3 | // RUN: %clang_cc1 -S %s -emit-llvm -triple x86_64-unknown-unknown -o - | FileCheck %s |
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| 4 | |
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| 5 | #include <stdint.h> |
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| 6 | |
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| 7 | // This test is meant to verify code that handles the 'p = nullptr + n' idiom |
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| 8 | // used by some versions of glibc and gcc. This is undefined behavior but |
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| 9 | // it is intended there to act like a conversion from a pointer-sized integer |
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| 10 | // to a pointer, and we would like to tolerate that. |
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| 11 | |
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| 12 | #define NULLPTRI8 ((int8_t*)0) |
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| 13 | |
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| 14 | // This should get the inttoptr instruction. |
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| 15 | int8_t *test1(intptr_t n) { |
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| 16 | return NULLPTRI8 + n; |
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| 17 | } |
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| 18 | // CHECK-LABEL: test1 |
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| 19 | // CHECK: inttoptr |
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| 20 | // CHECK-NOT: getelementptr |
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| 21 | |
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| 22 | // This doesn't meet the idiom because the element type is larger than a byte. |
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| 23 | int16_t *test2(intptr_t n) { |
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| 24 | return (int16_t*)0 + n; |
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| 25 | } |
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| 26 | // CHECK-LABEL: test2 |
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| 27 | // CHECK: getelementptr |
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| 28 | // CHECK-NOT: inttoptr |
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| 29 | |
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| 30 | // This doesn't meet the idiom because the offset is subtracted. |
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| 31 | int8_t* test3(intptr_t n) { |
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| 32 | return NULLPTRI8 - n; |
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| 33 | } |
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| 34 | // CHECK-LABEL: test3 |
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| 35 | // CHECK: getelementptr |
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| 36 | // CHECK-NOT: inttoptr |
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| 37 | |
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| 38 | // This checks the case where the offset isn't pointer-sized. |
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| 39 | // The front end will implicitly cast the offset to an integer, so we need to |
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| 40 | // make sure that doesn't cause problems on targets where integers and pointers |
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| 41 | // are not the same size. |
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| 42 | int8_t *test4(int8_t b) { |
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| 43 | return NULLPTRI8 + b; |
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| 44 | } |
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| 45 | // CHECK-LABEL: test4 |
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| 46 | // CHECK: inttoptr |
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| 47 | // CHECK-NOT: getelementptr |
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| 48 | |
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