Update SoftFloat

[riscv-isa-sim.git] / softfloat / s_approxRecipSqrt32_1.c

diff --git a/softfloat/s_approxRecipSqrt32_1.c b/softfloat/s_approxRecipSqrt32_1.c
index a3186739cd4b2a929e7d5e4f291bc3d0c719865a..2ab71a25a611ef88d558b7b68504b738dbf3fe8a 100644 (file)
--- a/softfloat/s_approxRecipSqrt32_1.c
+++ b/softfloat/s_approxRecipSqrt32_1.c
@@ -2,9 +2,9 @@
 /*============================================================================
 
 This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic
-Package, Release 3a, by John R. Hauser.
+Package, Release 3d, by John R. Hauser.
 
-Copyright 2011, 2012, 2013, 2014, 2015 The Regents of the University of
+Copyright 2011, 2012, 2013, 2014, 2015, 2016 The Regents of the University of
 California.  All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
@@ -39,34 +39,30 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #ifndef softfloat_approxRecipSqrt32_1
 
+extern const uint16_t softfloat_approxRecipSqrt_1k0s[];
+extern const uint16_t softfloat_approxRecipSqrt_1k1s[];
+
 uint32_t softfloat_approxRecipSqrt32_1( unsigned int oddExpA, uint32_t a )
 {
     int index;
-    uint16_t eps;
-    static const uint16_t k0s[] = {
-        0xB4C9, 0xFFAB, 0xAA7D, 0xF11C, 0xA1C5, 0xE4C7, 0x9A43, 0xDA29,
-        0x93B5, 0xD0E5, 0x8DED, 0xC8B7, 0x88C6, 0xC16D, 0x8424, 0xBAE1
-    };
-    static const uint16_t k1s[] = {
-        0xA5A5, 0xEA42, 0x8C21, 0xC62D, 0x788F, 0xAA7F, 0x6928, 0x94B6,
-        0x5CC7, 0x8335, 0x52A6, 0x74E2, 0x4A3E, 0x68FE, 0x432B, 0x5EFD
-    };
-    uint16_t r0;
+    uint16_t eps, r0;
     uint_fast32_t ESqrR0;
-    uint32_t delta0;
+    uint32_t sigma0;
     uint_fast32_t r;
-    uint32_t sqrDelta0;
+    uint32_t sqrSigma0;
 
     index = (a>>27 & 0xE) + oddExpA;
     eps = (uint16_t) (a>>12);
-    r0 = k0s[index] - ((k1s[index] * (uint_fast32_t) eps)>>20);
+    r0 = softfloat_approxRecipSqrt_1k0s[index]
+             - ((softfloat_approxRecipSqrt_1k1s[index] * (uint_fast32_t) eps)
+                    >>20);
     ESqrR0 = (uint_fast32_t) r0 * r0;
     if ( ! oddExpA ) ESqrR0 <<= 1;
-    delta0 = ~(uint_fast32_t) (((uint32_t) ESqrR0 * (uint_fast64_t) a)>>23);
-    r = ((uint_fast32_t) r0<<16) + ((r0 * (uint_fast64_t) delta0)>>25);
-    sqrDelta0 = ((uint_fast64_t) delta0 * delta0)>>32;
+    sigma0 = ~(uint_fast32_t) (((uint32_t) ESqrR0 * (uint_fast64_t) a)>>23);
+    r = ((uint_fast32_t) r0<<16) + ((r0 * (uint_fast64_t) sigma0)>>25);
+    sqrSigma0 = ((uint_fast64_t) sigma0 * sigma0)>>32;
     r += ((uint32_t) ((r>>1) + (r>>3) - ((uint_fast32_t) r0<<14))
-              * (uint_fast64_t) sqrDelta0)
+              * (uint_fast64_t) sqrSigma0)
              >>48;
     if ( ! (r & 0x80000000) ) r = 0x80000000;
     return r;