722460652b
Motorola treats denormals with explicit integer bit set as having unbiased exponent 0, unlike Intel which treats it as having unbiased exponent 1 (more like all other IEEE formats that have no explicit integer bit). Add a flag on FloatFmt to differentiate the behaviour. Reported-by: Keith Packard <keithp@keithp.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
54 lines
1.1 KiB
C
54 lines
1.1 KiB
C
/*
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* Test m68k extended double denormals.
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*/
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#include <stdio.h>
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#include <stdint.h>
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#define TEST(X, Y) { X, Y, X * Y }
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static volatile long double test[][3] = {
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TEST(0x1p+16383l, 0x1p-16446l),
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TEST(0x1.1p-8223l, 0x1.1p-8224l),
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TEST(1.0l, 0x1p-16383l),
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};
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#undef TEST
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static void dump_ld(const char *label, long double ld)
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{
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union {
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long double d;
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struct {
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uint32_t exp:16;
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uint32_t space:16;
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uint32_t h;
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uint32_t l;
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};
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} u;
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u.d = ld;
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printf("%12s: % -27La 0x%04x 0x%08x 0x%08x\n", label, u.d, u.exp, u.h, u.l);
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}
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int main(void)
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{
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int i, n = sizeof(test) / sizeof(test[0]), err = 0;
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for (i = 0; i < n; ++i) {
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long double x = test[i][0];
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long double y = test[i][1];
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long double build_mul = test[i][2];
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long double runtime_mul = x * y;
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if (runtime_mul != build_mul) {
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dump_ld("x", x);
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dump_ld("y", y);
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dump_ld("build_mul", build_mul);
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dump_ld("runtime_mul", runtime_mul);
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err = 1;
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}
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}
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return err;
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}
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