[v2,15/28] softfloat: Convert floatx80_div to FloatParts

Commit Message

Richard Henderson May 25, 2021, 3:06 p.m. UTC

Signed-off-by: Richard Henderson <[e-mail]>
---
 fpu/softfloat.c | 100 +++++++-----------------------------------------
 1 file changed, 13 insertions(+), 87 deletions(-)

Comments

Alex Bennée June 3, 2021, 2:23 p.m. UTC | #1

Richard Henderson <[e-mail]> writes:

> Signed-off-by: Richard Henderson <[e-mail]>

Reviewed-by: Alex Bennée <[e-mail]>

Patch

diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 2f2d1e50f7..7b9ae29285 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -2294,6 +2294,19 @@  float128_div(float128 a, float128 b, float_status *status)
     return float128_round_pack_canonical(pr, status);
 }
 
+floatx80 floatx80_div(floatx80 a, floatx80 b, float_status *status)
+{
+    FloatParts128 pa, pb, *pr;
+
+    if (!floatx80_unpack_canonical(&pa, a, status) ||
+        !floatx80_unpack_canonical(&pb, b, status)) {
+        return floatx80_default_nan(status);
+    }
+
+    pr = parts_div(&pa, &pb, status);
+    return floatx80_round_pack_canonical(pr, status);
+}
+
 /*
  * Float to Float conversions
  *
@@ -5880,93 +5893,6 @@  floatx80 floatx80_round_to_int(floatx80 a, float_status *status)
 
 }
 
-/*----------------------------------------------------------------------------
-| Returns the result of dividing the extended double-precision floating-point
-| value `a' by the corresponding value `b'.  The operation is performed
-| according to the IEC/IEEE Standard for Binary Floating-Point Arithmetic.
-*----------------------------------------------------------------------------*/
-
-floatx80 floatx80_div(floatx80 a, floatx80 b, float_status *status)
-{
-    bool aSign, bSign, zSign;
-    int32_t aExp, bExp, zExp;
-    uint64_t aSig, bSig, zSig0, zSig1;
-    uint64_t rem0, rem1, rem2, term0, term1, term2;
-
-    if (floatx80_invalid_encoding(a) || floatx80_invalid_encoding(b)) {
-        float_raise(float_flag_invalid, status);
-        return floatx80_default_nan(status);
-    }
-    aSig = extractFloatx80Frac( a );
-    aExp = extractFloatx80Exp( a );
-    aSign = extractFloatx80Sign( a );
-    bSig = extractFloatx80Frac( b );
-    bExp = extractFloatx80Exp( b );
-    bSign = extractFloatx80Sign( b );
-    zSign = aSign ^ bSign;
-    if ( aExp == 0x7FFF ) {
-        if ((uint64_t)(aSig << 1)) {
-            return propagateFloatx80NaN(a, b, status);
-        }
-        if ( bExp == 0x7FFF ) {
-            if ((uint64_t)(bSig << 1)) {
-                return propagateFloatx80NaN(a, b, status);
-            }
-            goto invalid;
-        }
-        return packFloatx80(zSign, floatx80_infinity_high,
-                                   floatx80_infinity_low);
-    }
-    if ( bExp == 0x7FFF ) {
-        if ((uint64_t)(bSig << 1)) {
-            return propagateFloatx80NaN(a, b, status);
-        }
-        return packFloatx80( zSign, 0, 0 );
-    }
-    if ( bExp == 0 ) {
-        if ( bSig == 0 ) {
-            if ( ( aExp | aSig ) == 0 ) {
- invalid:
-                float_raise(float_flag_invalid, status);
-                return floatx80_default_nan(status);
-            }
-            float_raise(float_flag_divbyzero, status);
-            return packFloatx80(zSign, floatx80_infinity_high,
-                                       floatx80_infinity_low);
-        }
-        normalizeFloatx80Subnormal( bSig, &bExp, &bSig );
-    }
-    if ( aExp == 0 ) {
-        if ( aSig == 0 ) return packFloatx80( zSign, 0, 0 );
-        normalizeFloatx80Subnormal( aSig, &aExp, &aSig );
-    }
-    zExp = aExp - bExp + 0x3FFE;
-    rem1 = 0;
-    if ( bSig <= aSig ) {
-        shift128Right( aSig, 0, 1, &aSig, &rem1 );
-        ++zExp;
-    }
-    zSig0 = estimateDiv128To64( aSig, rem1, bSig );
-    mul64To128( bSig, zSig0, &term0, &term1 );
-    sub128( aSig, rem1, term0, term1, &rem0, &rem1 );
-    while ( (int64_t) rem0 < 0 ) {
-        --zSig0;
-        add128( rem0, rem1, 0, bSig, &rem0, &rem1 );
-    }
-    zSig1 = estimateDiv128To64( rem1, 0, bSig );
-    if ( (uint64_t) ( zSig1<<1 ) <= 8 ) {
-        mul64To128( bSig, zSig1, &term1, &term2 );
-        sub128( rem1, 0, term1, term2, &rem1, &rem2 );
-        while ( (int64_t) rem1 < 0 ) {
-            --zSig1;
-            add128( rem1, rem2, 0, bSig, &rem1, &rem2 );
-        }
-        zSig1 |= ( ( rem1 | rem2 ) != 0 );
-    }
-    return roundAndPackFloatx80(status->floatx80_rounding_precision,
-                                zSign, zExp, zSig0, zSig1, status);
-}
-
 /*----------------------------------------------------------------------------
 | Returns the remainder of the extended double-precision floating-point value
 | `a' with respect to the corresponding value `b'.  The operation is performed