rewrite floatx80 bias unmasked overflow handling

bochs-emu · Apr 28, 2024 · 2059854 · 2059854
1 parent 89bfe81
commit 2059854
Showing 1 changed file with 29 additions and 33 deletions.
diff --git a/bochs/cpu/softfloat3e/s_roundPackToExtF80.c b/bochs/cpu/softfloat3e/s_roundPackToExtF80.c
@@ -40,7 +40,7 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include "softfloat.h"
 
 extFloat80_t
- SoftFloat_roundPackToExtF80(bool sign, int32_t exp, uint64_t sig, uint64_t sigExtra, uint8_t roundingPrecision, struct softfloat_status_t *status)
+ softfloat_roundPackToExtF80(bool sign, int32_t exp, uint64_t sig, uint64_t sigExtra, uint8_t roundingPrecision, struct softfloat_status_t *status)
 {
  uint8_t roundingMode;
  bool roundNearEven;
@@ -101,7 +101,13 @@ extFloat80_t
  }
  }
  if ((0x7FFE < exp) || ((exp == 0x7FFE) && ((uint64_t) (sig + roundIncrement) < sig))) {
- goto overflow;
+ if (! softfloat_isMaskedException(status, softfloat_flag_overflow)) {
+ softfloat_raiseFlags(status, softfloat_flag_overflow);
+ exp -= 0x6000;
+ }
+ else {
+ goto overflow;
+ }
  }
  }
  /*------------------------------------------------------------------------
@@ -169,23 +175,29 @@ extFloat80_t
  }
  }
  if ((0x7FFE < exp) || ((exp == 0x7FFE) && (sig == UINT64_C(0xFFFFFFFFFFFFFFFF)) && doIncrement)) {
- /*----------------------------------------------------------------
- *----------------------------------------------------------------*/
- roundMask = 0;
+ if (! softfloat_isMaskedException(status, softfloat_flag_overflow)) {
+ softfloat_raiseFlags(status, softfloat_flag_overflow);
+ exp -= 0x6000;
+ }
+ else {
+ /*----------------------------------------------------------------
+ *----------------------------------------------------------------*/
+ roundMask = 0;
  overflow:
- softfloat_raiseFlags(status, softfloat_flag_overflow | softfloat_flag_inexact);
- if (roundNearEven
- || (roundingMode == softfloat_round_near_maxMag)
- || (roundingMode == (sign ? softfloat_round_min : softfloat_round_max))
- ) {
- exp = 0x7FFF;
- sig = UINT64_C(0x8000000000000000);
- softfloat_setRoundingUp(status);
- } else {
- exp = 0x7FFE;
- sig = ~roundMask;
+ softfloat_raiseFlags(status, softfloat_flag_overflow | softfloat_flag_inexact);
+ if (roundNearEven
+ || (roundingMode == softfloat_round_near_maxMag)
+ || (roundingMode == (sign ? softfloat_round_min : softfloat_round_max))
+ ) {
+ exp = 0x7FFF;
+ sig = UINT64_C(0x8000000000000000);
+ softfloat_setRoundingUp(status);
+ } else {
+ exp = 0x7FFE;
+ sig = ~roundMask;
+ }
+ return packToExtF80(sign, exp, sig);
  }
- return packToExtF80(sign, exp, sig);
  }
  }
  /*------------------------------------------------------------------------
@@ -211,19 +223,3 @@ extFloat80_t
  }
  return packToExtF80(sign, exp, sig);
 }
-
-extFloat80_t
- softfloat_roundPackToExtF80(bool sign, int32_t exp, uint64_t sig, uint64_t sigExtra, uint8_t roundingPrecision, struct softfloat_status_t *status)
-{
- extFloat80_t result = SoftFloat_roundPackToExtF80(sign, exp, sig, sigExtra, roundingPrecision, status);
-
- // bias unmasked overflow
- if (status->softfloat_exceptionFlags & ~status->softfloat_exceptionMasks & softfloat_flag_overflow) {
- softfloat_status_t round_status = *status;
- softfloat_raiseFlags(&round_status, softfloat_flag_overflow);
- result = SoftFloat_roundPackToExtF80(sign, exp - 0x6000, sig, sigExtra, roundingPrecision, &round_status);
- *status = round_status;
- }
-
- return result;
-}