Refactor addsf3.c and adddf3.c.

Differential Revision: http://reviews.llvm.org/D3885

llvm-svn: 209740
diff --git a/compiler-rt/lib/builtins/adddf3.c b/compiler-rt/lib/builtins/adddf3.c
index 7f19667..8b7aae0 100644
--- a/compiler-rt/lib/builtins/adddf3.c
+++ b/compiler-rt/lib/builtins/adddf3.c
@@ -13,140 +13,10 @@
 //===----------------------------------------------------------------------===//
 
 #define DOUBLE_PRECISION
-#include "fp_lib.h"
+#include "fp_add_impl.inc"
 
 ARM_EABI_FNALIAS(dadd, adddf3)
 
-COMPILER_RT_ABI fp_t
-__adddf3(fp_t a, fp_t b) {
-    
-    rep_t aRep = toRep(a);
-    rep_t bRep = toRep(b);
-    const rep_t aAbs = aRep & absMask;
-    const rep_t bAbs = bRep & absMask;
-    
-    // Detect if a or b is zero, infinity, or NaN.
-    if (aAbs - 1U >= infRep - 1U || bAbs - 1U >= infRep - 1U) {
-        
-        // NaN + anything = qNaN
-        if (aAbs > infRep) return fromRep(toRep(a) | quietBit);
-        // anything + NaN = qNaN
-        if (bAbs > infRep) return fromRep(toRep(b) | quietBit);
-        
-        if (aAbs == infRep) {
-            // +/-infinity + -/+infinity = qNaN
-            if ((toRep(a) ^ toRep(b)) == signBit) return fromRep(qnanRep);
-            // +/-infinity + anything remaining = +/- infinity
-            else return a;
-        }
-        
-        // anything remaining + +/-infinity = +/-infinity
-        if (bAbs == infRep) return b;
-        
-        // zero + anything = anything
-        if (!aAbs) {
-            // but we need to get the sign right for zero + zero
-            if (!bAbs) return fromRep(toRep(a) & toRep(b));
-            else return b;
-        }
-        
-        // anything + zero = anything
-        if (!bAbs) return a;
-    }
-    
-    // Swap a and b if necessary so that a has the larger absolute value.
-    if (bAbs > aAbs) {
-        const rep_t temp = aRep;
-        aRep = bRep;
-        bRep = temp;
-    }
-    
-    // Extract the exponent and significand from the (possibly swapped) a and b.
-    int aExponent = aRep >> significandBits & maxExponent;
-    int bExponent = bRep >> significandBits & maxExponent;
-    rep_t aSignificand = aRep & significandMask;
-    rep_t bSignificand = bRep & significandMask;
-    
-    // Normalize any denormals, and adjust the exponent accordingly.
-    if (aExponent == 0) aExponent = normalize(&aSignificand);
-    if (bExponent == 0) bExponent = normalize(&bSignificand);
-    
-    // The sign of the result is the sign of the larger operand, a.  If they
-    // have opposite signs, we are performing a subtraction; otherwise addition.
-    const rep_t resultSign = aRep & signBit;
-    const bool subtraction = (aRep ^ bRep) & signBit;
-    
-    // Shift the significands to give us round, guard and sticky, and or in the
-    // implicit significand bit.  (If we fell through from the denormal path it
-    // was already set by normalize( ), but setting it twice won't hurt
-    // anything.)
-    aSignificand = (aSignificand | implicitBit) << 3;
-    bSignificand = (bSignificand | implicitBit) << 3;
-    
-    // Shift the significand of b by the difference in exponents, with a sticky
-    // bottom bit to get rounding correct.
-    const unsigned int align = aExponent - bExponent;
-    if (align) {
-        if (align < typeWidth) {
-            const bool sticky = bSignificand << (typeWidth - align);
-            bSignificand = bSignificand >> align | sticky;
-        } else {
-            bSignificand = 1; // sticky; b is known to be non-zero.
-        }
-    }
-    
-    if (subtraction) {
-        aSignificand -= bSignificand;
-        
-        // If a == -b, return +zero.
-        if (aSignificand == 0) return fromRep(0);
-        
-        // If partial cancellation occurred, we need to left-shift the result
-        // and adjust the exponent:
-        if (aSignificand < implicitBit << 3) {
-            const int shift = rep_clz(aSignificand) - rep_clz(implicitBit << 3);
-            aSignificand <<= shift;
-            aExponent -= shift;
-        }
-    }
-    
-    else /* addition */ {
-        aSignificand += bSignificand;
-        
-        // If the addition carried up, we need to right-shift the result and
-        // adjust the exponent:
-        if (aSignificand & implicitBit << 4) {
-            const bool sticky = aSignificand & 1;
-            aSignificand = aSignificand >> 1 | sticky;
-            aExponent += 1;
-        }
-    }
-    
-    // If we have overflowed the type, return +/- infinity:
-    if (aExponent >= maxExponent) return fromRep(infRep | resultSign);
-    
-    if (aExponent <= 0) {
-        // Result is denormal before rounding; the exponent is zero and we
-        // need to shift the significand.
-        const int shift = 1 - aExponent;
-        const bool sticky = aSignificand << (typeWidth - shift);
-        aSignificand = aSignificand >> shift | sticky;
-        aExponent = 0;
-    }
-    
-    // Low three bits are round, guard, and sticky.
-    const int roundGuardSticky = aSignificand & 0x7;
-    
-    // Shift the significand into place, and mask off the implicit bit.
-    rep_t result = aSignificand >> 3 & significandMask;
-    
-    // Insert the exponent and sign.
-    result |= (rep_t)aExponent << significandBits;
-    result |= resultSign;
-    
-    // Final rounding.  The result may overflow to infinity, but that is the
-    // correct result in that case.
-    if (roundGuardSticky > 0x4) result++;
-    if (roundGuardSticky == 0x4) result += result & 1;
-    return fromRep(result);
+COMPILER_RT_ABI double __adddf3(double a, double b){
+    return __addXf3__(a, b);
 }