18c53e1e73
The fbstp implementation stores +0 when the rounded result should be -0 because it compares an integer value with 0 to determine the sign. Fix this by checking the sign bit of the operand instead. Signed-off-by: Joseph Myers <joseph@codesourcery.com> Message-Id: <alpine.DEB.2.21.2005132350230.11687@digraph.polyomino.org.uk> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
26 lines
651 B
C
26 lines
651 B
C
/* Test fbstp instruction. */
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#include <stdio.h>
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#include <string.h>
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int main(void)
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{
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int ret = 0;
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unsigned char out[10];
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memset(out, 0xfe, sizeof out);
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__asm__ volatile ("fbstp %0" : "=m" (out) : "t" (-0.0L) : "st");
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out[9] &= 0x80;
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if (memcmp(out, "\0\0\0\0\0\0\0\0\0\x80", sizeof out) != 0) {
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printf("FAIL: fbstp -0\n");
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ret = 1;
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}
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memset(out, 0x12, sizeof out);
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__asm__ volatile ("fbstp %0" : "=m" (out) : "t" (-0.1L) : "st");
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out[9] &= 0x80;
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if (memcmp(out, "\0\0\0\0\0\0\0\0\0\x80", sizeof out) != 0) {
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printf("FAIL: fbstp -0.1\n");
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ret = 1;
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}
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return ret;
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}
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