50 lines
1.3 KiB
C
50 lines
1.3 KiB
C
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typedef unsigned long long uint64_t;
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void abort (void);
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#define BASE 0x1234567812345678ull
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#define DEF_BBIT_TAKEN(BRANCH_IF, BIT) \
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int bbit_is_taken_##BRANCH_IF##_##BIT (volatile uint64_t *p) \
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{ \
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int ret; \
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asm (".set push \n\t" \
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".set noreorder \n\t" \
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"bbit" #BRANCH_IF " %1, " #BIT ", 1f \n\t" \
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"nop \n\t" \
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"li %0, 0 \n\t" \
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"b 2f \n\t" \
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"nop \n\t" \
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"1: \n\t" \
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"li %0, 1 \n\t" \
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"2: \n\t" \
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".set pop" \
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: "=r"(ret) : "r"(*p)); \
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return ret; \
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} \
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volatile uint64_t taken_##BRANCH_IF##_##BIT = \
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BASE & (~(1ull << BIT)) | ((uint64_t) BRANCH_IF << BIT); \
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volatile uint64_t not_taken_##BRANCH_IF##_##BIT = \
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BASE & (~(1ull << BIT)) | (((uint64_t) !BRANCH_IF) << BIT);
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DEF_BBIT_TAKEN (0, 10);
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DEF_BBIT_TAKEN (0, 36);
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DEF_BBIT_TAKEN (1, 20);
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DEF_BBIT_TAKEN (1, 49);
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#define EXPECT(X) if (!(X)) abort ();
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main ()
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{
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EXPECT (bbit_is_taken_0_10 (&taken_0_10));
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EXPECT (!bbit_is_taken_0_10 (¬_taken_0_10));
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EXPECT (bbit_is_taken_0_36 (&taken_0_36));
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EXPECT (!bbit_is_taken_0_36 (¬_taken_0_36));
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EXPECT (bbit_is_taken_1_20 (&taken_1_20));
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EXPECT (!bbit_is_taken_1_20 (¬_taken_1_20));
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EXPECT (bbit_is_taken_1_49 (&taken_1_49));
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EXPECT (!bbit_is_taken_1_49 (¬_taken_1_49));
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}
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