diff options
| -rw-r--r-- | fpu/softfloat.c | 6 | ||||
| -rw-r--r-- | tests/tcg/i386/test-i386-pseudo-denormal.c | 24 |
2 files changed, 30 insertions, 0 deletions
diff --git a/fpu/softfloat.c b/fpu/softfloat.c index ac116c7..6094d26 100644 --- a/fpu/softfloat.c +++ b/fpu/softfloat.c @@ -5866,6 +5866,12 @@ static floatx80 addFloatx80Sigs(floatx80 a, floatx80 b, flag zSign, zSig1 = 0; zSig0 = aSig + bSig; if ( aExp == 0 ) { + if ((aSig | bSig) & UINT64_C(0x8000000000000000) && zSig0 < aSig) { + /* At least one of the values is a pseudo-denormal, + * and there is a carry out of the result. */ + zExp = 1; + goto shiftRight1; + } if (zSig0 == 0) { return packFloatx80(zSign, 0, 0); } diff --git a/tests/tcg/i386/test-i386-pseudo-denormal.c b/tests/tcg/i386/test-i386-pseudo-denormal.c new file mode 100644 index 0000000..cfa2a50 --- /dev/null +++ b/tests/tcg/i386/test-i386-pseudo-denormal.c @@ -0,0 +1,24 @@ +/* Test pseudo-denormal operations. */ + +#include <stdint.h> +#include <stdio.h> + +union u { + struct { uint64_t sig; uint16_t sign_exp; } s; + long double ld; +}; + +volatile union u ld_pseudo_m16382 = { .s = { UINT64_C(1) << 63, 0 } }; + +volatile long double ld_res; + +int main(void) +{ + int ret = 0; + ld_res = ld_pseudo_m16382.ld + ld_pseudo_m16382.ld; + if (ld_res != 0x1p-16381L) { + printf("FAIL: pseudo-denormal add\n"); + ret = 1; + } + return ret; +} |