Szabolcs Nagy
c4359e0130
old code was correct only if the result was stored (without the excess precision) or musl was compiled with -ffloat-store. now we use STRICT_ASSIGN to work around the issue. (see note 160 in c11 section 6.8.6.4)
34 lines
534 B
C
34 lines
534 B
C
#include "libm.h"
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float scalbnf(float x, int n)
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{
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float scale;
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if (n > 127) {
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x *= 0x1p127f;
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n -= 127;
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if (n > 127) {
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x *= 0x1p127f;
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n -= 127;
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if (n > 127) {
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STRICT_ASSIGN(float, x, x * 0x1p127f);
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return x;
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}
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}
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} else if (n < -126) {
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x *= 0x1p-126f;
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n += 126;
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if (n < -126) {
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x *= 0x1p-126f;
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n += 126;
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if (n < -126) {
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STRICT_ASSIGN(float, x, x * 0x1p-126f);
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return x;
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}
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}
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}
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SET_FLOAT_WORD(scale, (uint32_t)(0x7f+n)<<23);
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STRICT_ASSIGN(float, x, x * scale);
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return x;
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}
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