1 files changed, 74 insertions, 0 deletions
diff --git a/softfloat/f64_sqrt.c b/softfloat/f64_sqrt.c
new file mode 100755
index 0000000..cd91010
--- /dev/null
+++ b/softfloat/f64_sqrt.c
@@ -0,0 +1,74 @@
+
+#include <stdbool.h>
+#include <stdint.h>
+#include "platform.h"
+#include "primitives.h"
+#include "internals.h"
+#include "specialize.h"
+#include "softfloat.h"
+
+float64_t f64_sqrt( float64_t a )
+{
+    union ui64_f64 uA;
+    uint_fast64_t uiA;
+    bool signA;
+    int_fast16_t expA;
+    uint_fast64_t sigA, uiZ;
+    struct exp16_sig64 normExpSig;
+    int_fast16_t expZ;
+    uint_fast32_t sigZ32;
+    uint_fast64_t sigZ;
+    struct uint128 term, rem;
+    union ui64_f64 uZ;
+
+    uA.f = a;
+    uiA = uA.ui;
+    signA = signF64UI( uiA );
+    expA = expF64UI( uiA );
+    sigA = fracF64UI( uiA );
+    if ( expA == 0x7FF ) {
+        if ( sigA ) {
+            uiZ = softfloat_propagateNaNF64UI( uiA, 0 );
+            goto uiZ;
+        }
+        if ( ! signA ) return a;
+        goto invalid;
+    }
+    if ( signA ) {
+        if ( ! ( expA | sigA ) ) return a;
+        goto invalid;
+    }
+    if ( ! expA ) {
+        if ( ! sigA ) return a;
+        normExpSig = softfloat_normSubnormalF64Sig( sigA );
+        expA = normExpSig.exp;
+        sigA = normExpSig.sig;
+    }
+    expZ = ( ( expA - 0x3FF )>>1 ) + 0x3FE;
+    sigA |= UINT64_C( 0x0010000000000000 );
+    sigZ32 = softfloat_estimateSqrt32( expA, sigA>>21 );
+    sigA <<= 9 - ( expA & 1 );
+    sigZ =
+        softfloat_estimateDiv128To64( sigA, 0, (uint_fast64_t) sigZ32<<32 )
+            + ( (uint_fast64_t) sigZ32<<30 );
+    if ( ( sigZ & 0x1FF ) <= 5 ) {
+        term = softfloat_mul64To128( sigZ, sigZ );
+        rem = softfloat_sub128( sigA, 0, term.v64, term.v0 );
+        while ( UINT64_C( 0x8000000000000000 ) <= rem.v64 ) {
+            --sigZ;
+            rem =
+                softfloat_add128(
+                    rem.v64, rem.v0, sigZ>>63, (uint64_t) ( sigZ<<1 ) );
+        }
+        sigZ |= ( ( rem.v64 | rem.v0 ) != 0 );
+    }
+    return softfloat_roundPackToF64( 0, expZ, sigZ );
+ invalid:
+    softfloat_raiseFlags( softfloat_flag_invalid );
+    uiZ = defaultNaNF64UI;
+ uiZ:
+    uZ.ui = uiZ;
+    return uZ.f;
+
+}
+