[compiler-rt] r209740 - Refactor addsf3.c and adddf3.c.

Joerg Sonnenberger joerg at bec.de
Wed May 28 08:06:25 PDT 2014


Author: joerg
Date: Wed May 28 10:06:25 2014
New Revision: 209740

URL: http://llvm.org/viewvc/llvm-project?rev=209740&view=rev
Log:
Refactor addsf3.c and adddf3.c.

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

Added:
    compiler-rt/trunk/lib/builtins/fp_add_impl.inc
Modified:
    compiler-rt/trunk/lib/builtins/adddf3.c
    compiler-rt/trunk/lib/builtins/addsf3.c

Modified: compiler-rt/trunk/lib/builtins/adddf3.c
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/builtins/adddf3.c?rev=209740&r1=209739&r2=209740&view=diff
==============================================================================
--- compiler-rt/trunk/lib/builtins/adddf3.c (original)
+++ compiler-rt/trunk/lib/builtins/adddf3.c Wed May 28 10:06:25 2014
@@ -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);
 }

Modified: compiler-rt/trunk/lib/builtins/addsf3.c
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/builtins/addsf3.c?rev=209740&r1=209739&r2=209740&view=diff
==============================================================================
--- compiler-rt/trunk/lib/builtins/addsf3.c (original)
+++ compiler-rt/trunk/lib/builtins/addsf3.c Wed May 28 10:06:25 2014
@@ -13,140 +13,10 @@
 //===----------------------------------------------------------------------===//
 
 #define SINGLE_PRECISION
-#include "fp_lib.h"
+#include "fp_add_impl.inc"
 
 ARM_EABI_FNALIAS(fadd, addsf3)
 
-COMPILER_RT_ABI fp_t
-__addsf3(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 float __addsf3(float a, float b) {
+    return __addXf3__(a, b);
 }

Added: compiler-rt/trunk/lib/builtins/fp_add_impl.inc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/builtins/fp_add_impl.inc?rev=209740&view=auto
==============================================================================
--- compiler-rt/trunk/lib/builtins/fp_add_impl.inc (added)
+++ compiler-rt/trunk/lib/builtins/fp_add_impl.inc Wed May 28 10:06:25 2014
@@ -0,0 +1,144 @@
+//===----- lib/fp_add_impl.inc - floaing point addition -----------*- C -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements soft-float addition with the IEEE-754 default rounding
+// (to nearest, ties to even).
+//
+//===----------------------------------------------------------------------===//
+
+#include "fp_lib.h"
+
+static inline fp_t __addXf3__(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 - REP_C(1) >= infRep - REP_C(1) ||
+        bAbs - REP_C(1) >= infRep - REP_C(1)) {
+        // 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 occured, 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);
+}





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