931 lines
		
	
	
		
			22 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			931 lines
		
	
	
		
			22 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
 | |
|  * Floating point emulation support for subnormalised numbers on SH4
 | |
|  * architecture This file is derived from the SoftFloat IEC/IEEE
 | |
|  * Floating-point Arithmetic Package, Release 2 the original license of
 | |
|  * which is reproduced below.
 | |
|  *
 | |
|  * ========================================================================
 | |
|  *
 | |
|  * This C source file is part of the SoftFloat IEC/IEEE Floating-point
 | |
|  * Arithmetic Package, Release 2.
 | |
|  *
 | |
|  * Written by John R. Hauser.  This work was made possible in part by the
 | |
|  * International Computer Science Institute, located at Suite 600, 1947 Center
 | |
|  * Street, Berkeley, California 94704.  Funding was partially provided by the
 | |
|  * National Science Foundation under grant MIP-9311980.  The original version
 | |
|  * of this code was written as part of a project to build a fixed-point vector
 | |
|  * processor in collaboration with the University of California at Berkeley,
 | |
|  * overseen by Profs. Nelson Morgan and John Wawrzynek.  More information
 | |
|  * is available through the web page `http://HTTP.CS.Berkeley.EDU/~jhauser/
 | |
|  * arithmetic/softfloat.html'.
 | |
|  *
 | |
|  * THIS SOFTWARE IS DISTRIBUTED AS IS, FOR FREE.  Although reasonable effort
 | |
|  * has been made to avoid it, THIS SOFTWARE MAY CONTAIN FAULTS THAT WILL AT
 | |
|  * TIMES RESULT IN INCORRECT BEHAVIOR.  USE OF THIS SOFTWARE IS RESTRICTED TO
 | |
|  * PERSONS AND ORGANIZATIONS WHO CAN AND WILL TAKE FULL RESPONSIBILITY FOR ANY
 | |
|  * AND ALL LOSSES, COSTS, OR OTHER PROBLEMS ARISING FROM ITS USE.
 | |
|  *
 | |
|  * Derivative works are acceptable, even for commercial purposes, so long as
 | |
|  * (1) they include prominent notice that the work is derivative, and (2) they
 | |
|  * include prominent notice akin to these three paragraphs for those parts of
 | |
|  * this code that are retained.
 | |
|  *
 | |
|  * ========================================================================
 | |
|  *
 | |
|  * SH4 modifications by Ismail Dhaoui <ismail.dhaoui@st.com>
 | |
|  * and Kamel Khelifi <kamel.khelifi@st.com>
 | |
|  */
 | |
| #include <linux/kernel.h>
 | |
| #include <cpu/fpu.h>
 | |
| #include <asm/div64.h>
 | |
| 
 | |
| #define LIT64( a ) a##LL
 | |
| 
 | |
| typedef char flag;
 | |
| typedef unsigned char uint8;
 | |
| typedef signed char int8;
 | |
| typedef int uint16;
 | |
| typedef int int16;
 | |
| typedef unsigned int uint32;
 | |
| typedef signed int int32;
 | |
| 
 | |
| typedef unsigned long long int bits64;
 | |
| typedef signed long long int sbits64;
 | |
| 
 | |
| typedef unsigned char bits8;
 | |
| typedef signed char sbits8;
 | |
| typedef unsigned short int bits16;
 | |
| typedef signed short int sbits16;
 | |
| typedef unsigned int bits32;
 | |
| typedef signed int sbits32;
 | |
| 
 | |
| typedef unsigned long long int uint64;
 | |
| typedef signed long long int int64;
 | |
| 
 | |
| typedef unsigned long int float32;
 | |
| typedef unsigned long long float64;
 | |
| 
 | |
| extern void float_raise(unsigned int flags);	/* in fpu.c */
 | |
| extern int float_rounding_mode(void);	/* in fpu.c */
 | |
| 
 | |
| bits64 extractFloat64Frac(float64 a);
 | |
| flag extractFloat64Sign(float64 a);
 | |
| int16 extractFloat64Exp(float64 a);
 | |
| int16 extractFloat32Exp(float32 a);
 | |
| flag extractFloat32Sign(float32 a);
 | |
| bits32 extractFloat32Frac(float32 a);
 | |
| float64 packFloat64(flag zSign, int16 zExp, bits64 zSig);
 | |
| void shift64RightJamming(bits64 a, int16 count, bits64 * zPtr);
 | |
| float32 packFloat32(flag zSign, int16 zExp, bits32 zSig);
 | |
| void shift32RightJamming(bits32 a, int16 count, bits32 * zPtr);
 | |
| float64 float64_sub(float64 a, float64 b);
 | |
| float32 float32_sub(float32 a, float32 b);
 | |
| float32 float32_add(float32 a, float32 b);
 | |
| float64 float64_add(float64 a, float64 b);
 | |
| float64 float64_div(float64 a, float64 b);
 | |
| float32 float32_div(float32 a, float32 b);
 | |
| float32 float32_mul(float32 a, float32 b);
 | |
| float64 float64_mul(float64 a, float64 b);
 | |
| float32 float64_to_float32(float64 a);
 | |
| void add128(bits64 a0, bits64 a1, bits64 b0, bits64 b1, bits64 * z0Ptr,
 | |
| 		   bits64 * z1Ptr);
 | |
| void sub128(bits64 a0, bits64 a1, bits64 b0, bits64 b1, bits64 * z0Ptr,
 | |
| 		   bits64 * z1Ptr);
 | |
| void mul64To128(bits64 a, bits64 b, bits64 * z0Ptr, bits64 * z1Ptr);
 | |
| 
 | |
| static int8 countLeadingZeros32(bits32 a);
 | |
| static int8 countLeadingZeros64(bits64 a);
 | |
| static float64 normalizeRoundAndPackFloat64(flag zSign, int16 zExp,
 | |
| 					    bits64 zSig);
 | |
| static float64 subFloat64Sigs(float64 a, float64 b, flag zSign);
 | |
| static float64 addFloat64Sigs(float64 a, float64 b, flag zSign);
 | |
| static float32 roundAndPackFloat32(flag zSign, int16 zExp, bits32 zSig);
 | |
| static float32 normalizeRoundAndPackFloat32(flag zSign, int16 zExp,
 | |
| 					    bits32 zSig);
 | |
| static float64 roundAndPackFloat64(flag zSign, int16 zExp, bits64 zSig);
 | |
| static float32 subFloat32Sigs(float32 a, float32 b, flag zSign);
 | |
| static float32 addFloat32Sigs(float32 a, float32 b, flag zSign);
 | |
| static void normalizeFloat64Subnormal(bits64 aSig, int16 * zExpPtr,
 | |
| 				      bits64 * zSigPtr);
 | |
| static bits64 estimateDiv128To64(bits64 a0, bits64 a1, bits64 b);
 | |
| static void normalizeFloat32Subnormal(bits32 aSig, int16 * zExpPtr,
 | |
| 				      bits32 * zSigPtr);
 | |
| 
 | |
| bits64 extractFloat64Frac(float64 a)
 | |
| {
 | |
| 	return a & LIT64(0x000FFFFFFFFFFFFF);
 | |
| }
 | |
| 
 | |
| flag extractFloat64Sign(float64 a)
 | |
| {
 | |
| 	return a >> 63;
 | |
| }
 | |
| 
 | |
| int16 extractFloat64Exp(float64 a)
 | |
| {
 | |
| 	return (a >> 52) & 0x7FF;
 | |
| }
 | |
| 
 | |
| int16 extractFloat32Exp(float32 a)
 | |
| {
 | |
| 	return (a >> 23) & 0xFF;
 | |
| }
 | |
| 
 | |
| flag extractFloat32Sign(float32 a)
 | |
| {
 | |
| 	return a >> 31;
 | |
| }
 | |
| 
 | |
| bits32 extractFloat32Frac(float32 a)
 | |
| {
 | |
| 	return a & 0x007FFFFF;
 | |
| }
 | |
| 
 | |
| float64 packFloat64(flag zSign, int16 zExp, bits64 zSig)
 | |
| {
 | |
| 	return (((bits64) zSign) << 63) + (((bits64) zExp) << 52) + zSig;
 | |
| }
 | |
| 
 | |
| void shift64RightJamming(bits64 a, int16 count, bits64 * zPtr)
 | |
| {
 | |
| 	bits64 z;
 | |
| 
 | |
| 	if (count == 0) {
 | |
| 		z = a;
 | |
| 	} else if (count < 64) {
 | |
| 		z = (a >> count) | ((a << ((-count) & 63)) != 0);
 | |
| 	} else {
 | |
| 		z = (a != 0);
 | |
| 	}
 | |
| 	*zPtr = z;
 | |
| }
 | |
| 
 | |
| static int8 countLeadingZeros32(bits32 a)
 | |
| {
 | |
| 	static const int8 countLeadingZerosHigh[] = {
 | |
| 		8, 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4,
 | |
| 		3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
 | |
| 		2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
 | |
| 		2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
 | |
| 		1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
 | |
| 		1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
 | |
| 		1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
 | |
| 		1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
 | |
| 		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 | |
| 		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 | |
| 		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 | |
| 		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 | |
| 		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 | |
| 		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 | |
| 		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 | |
| 		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
 | |
| 	};
 | |
| 	int8 shiftCount;
 | |
| 
 | |
| 	shiftCount = 0;
 | |
| 	if (a < 0x10000) {
 | |
| 		shiftCount += 16;
 | |
| 		a <<= 16;
 | |
| 	}
 | |
| 	if (a < 0x1000000) {
 | |
| 		shiftCount += 8;
 | |
| 		a <<= 8;
 | |
| 	}
 | |
| 	shiftCount += countLeadingZerosHigh[a >> 24];
 | |
| 	return shiftCount;
 | |
| 
 | |
| }
 | |
| 
 | |
| static int8 countLeadingZeros64(bits64 a)
 | |
| {
 | |
| 	int8 shiftCount;
 | |
| 
 | |
| 	shiftCount = 0;
 | |
| 	if (a < ((bits64) 1) << 32) {
 | |
| 		shiftCount += 32;
 | |
| 	} else {
 | |
| 		a >>= 32;
 | |
| 	}
 | |
| 	shiftCount += countLeadingZeros32(a);
 | |
| 	return shiftCount;
 | |
| 
 | |
| }
 | |
| 
 | |
| static float64 normalizeRoundAndPackFloat64(flag zSign, int16 zExp, bits64 zSig)
 | |
| {
 | |
| 	int8 shiftCount;
 | |
| 
 | |
| 	shiftCount = countLeadingZeros64(zSig) - 1;
 | |
| 	return roundAndPackFloat64(zSign, zExp - shiftCount,
 | |
| 				   zSig << shiftCount);
 | |
| 
 | |
| }
 | |
| 
 | |
| static float64 subFloat64Sigs(float64 a, float64 b, flag zSign)
 | |
| {
 | |
| 	int16 aExp, bExp, zExp;
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| 	bits64 aSig, bSig, zSig;
 | |
| 	int16 expDiff;
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| 
 | |
| 	aSig = extractFloat64Frac(a);
 | |
| 	aExp = extractFloat64Exp(a);
 | |
| 	bSig = extractFloat64Frac(b);
 | |
| 	bExp = extractFloat64Exp(b);
 | |
| 	expDiff = aExp - bExp;
 | |
| 	aSig <<= 10;
 | |
| 	bSig <<= 10;
 | |
| 	if (0 < expDiff)
 | |
| 		goto aExpBigger;
 | |
| 	if (expDiff < 0)
 | |
| 		goto bExpBigger;
 | |
| 	if (aExp == 0) {
 | |
| 		aExp = 1;
 | |
| 		bExp = 1;
 | |
| 	}
 | |
| 	if (bSig < aSig)
 | |
| 		goto aBigger;
 | |
| 	if (aSig < bSig)
 | |
| 		goto bBigger;
 | |
| 	return packFloat64(float_rounding_mode() == FPSCR_RM_ZERO, 0, 0);
 | |
|       bExpBigger:
 | |
| 	if (bExp == 0x7FF) {
 | |
| 		return packFloat64(zSign ^ 1, 0x7FF, 0);
 | |
| 	}
 | |
| 	if (aExp == 0) {
 | |
| 		++expDiff;
 | |
| 	} else {
 | |
| 		aSig |= LIT64(0x4000000000000000);
 | |
| 	}
 | |
| 	shift64RightJamming(aSig, -expDiff, &aSig);
 | |
| 	bSig |= LIT64(0x4000000000000000);
 | |
|       bBigger:
 | |
| 	zSig = bSig - aSig;
 | |
| 	zExp = bExp;
 | |
| 	zSign ^= 1;
 | |
| 	goto normalizeRoundAndPack;
 | |
|       aExpBigger:
 | |
| 	if (aExp == 0x7FF) {
 | |
| 		return a;
 | |
| 	}
 | |
| 	if (bExp == 0) {
 | |
| 		--expDiff;
 | |
| 	} else {
 | |
| 		bSig |= LIT64(0x4000000000000000);
 | |
| 	}
 | |
| 	shift64RightJamming(bSig, expDiff, &bSig);
 | |
| 	aSig |= LIT64(0x4000000000000000);
 | |
|       aBigger:
 | |
| 	zSig = aSig - bSig;
 | |
| 	zExp = aExp;
 | |
|       normalizeRoundAndPack:
 | |
| 	--zExp;
 | |
| 	return normalizeRoundAndPackFloat64(zSign, zExp, zSig);
 | |
| 
 | |
| }
 | |
| static float64 addFloat64Sigs(float64 a, float64 b, flag zSign)
 | |
| {
 | |
| 	int16 aExp, bExp, zExp;
 | |
| 	bits64 aSig, bSig, zSig;
 | |
| 	int16 expDiff;
 | |
| 
 | |
| 	aSig = extractFloat64Frac(a);
 | |
| 	aExp = extractFloat64Exp(a);
 | |
| 	bSig = extractFloat64Frac(b);
 | |
| 	bExp = extractFloat64Exp(b);
 | |
| 	expDiff = aExp - bExp;
 | |
| 	aSig <<= 9;
 | |
| 	bSig <<= 9;
 | |
| 	if (0 < expDiff) {
 | |
| 		if (aExp == 0x7FF) {
 | |
| 			return a;
 | |
| 		}
 | |
| 		if (bExp == 0) {
 | |
| 			--expDiff;
 | |
| 		} else {
 | |
| 			bSig |= LIT64(0x2000000000000000);
 | |
| 		}
 | |
| 		shift64RightJamming(bSig, expDiff, &bSig);
 | |
| 		zExp = aExp;
 | |
| 	} else if (expDiff < 0) {
 | |
| 		if (bExp == 0x7FF) {
 | |
| 			return packFloat64(zSign, 0x7FF, 0);
 | |
| 		}
 | |
| 		if (aExp == 0) {
 | |
| 			++expDiff;
 | |
| 		} else {
 | |
| 			aSig |= LIT64(0x2000000000000000);
 | |
| 		}
 | |
| 		shift64RightJamming(aSig, -expDiff, &aSig);
 | |
| 		zExp = bExp;
 | |
| 	} else {
 | |
| 		if (aExp == 0x7FF) {
 | |
| 			return a;
 | |
| 		}
 | |
| 		if (aExp == 0)
 | |
| 			return packFloat64(zSign, 0, (aSig + bSig) >> 9);
 | |
| 		zSig = LIT64(0x4000000000000000) + aSig + bSig;
 | |
| 		zExp = aExp;
 | |
| 		goto roundAndPack;
 | |
| 	}
 | |
| 	aSig |= LIT64(0x2000000000000000);
 | |
| 	zSig = (aSig + bSig) << 1;
 | |
| 	--zExp;
 | |
| 	if ((sbits64) zSig < 0) {
 | |
| 		zSig = aSig + bSig;
 | |
| 		++zExp;
 | |
| 	}
 | |
|       roundAndPack:
 | |
| 	return roundAndPackFloat64(zSign, zExp, zSig);
 | |
| 
 | |
| }
 | |
| 
 | |
| float32 packFloat32(flag zSign, int16 zExp, bits32 zSig)
 | |
| {
 | |
| 	return (((bits32) zSign) << 31) + (((bits32) zExp) << 23) + zSig;
 | |
| }
 | |
| 
 | |
| void shift32RightJamming(bits32 a, int16 count, bits32 * zPtr)
 | |
| {
 | |
| 	bits32 z;
 | |
| 	if (count == 0) {
 | |
| 		z = a;
 | |
| 	} else if (count < 32) {
 | |
| 		z = (a >> count) | ((a << ((-count) & 31)) != 0);
 | |
| 	} else {
 | |
| 		z = (a != 0);
 | |
| 	}
 | |
| 	*zPtr = z;
 | |
| }
 | |
| 
 | |
| static float32 roundAndPackFloat32(flag zSign, int16 zExp, bits32 zSig)
 | |
| {
 | |
| 	flag roundNearestEven;
 | |
| 	int8 roundIncrement, roundBits;
 | |
| 	flag isTiny;
 | |
| 
 | |
| 	/* SH4 has only 2 rounding modes - round to nearest and round to zero */
 | |
| 	roundNearestEven = (float_rounding_mode() == FPSCR_RM_NEAREST);
 | |
| 	roundIncrement = 0x40;
 | |
| 	if (!roundNearestEven) {
 | |
| 		roundIncrement = 0;
 | |
| 	}
 | |
| 	roundBits = zSig & 0x7F;
 | |
| 	if (0xFD <= (bits16) zExp) {
 | |
| 		if ((0xFD < zExp)
 | |
| 		    || ((zExp == 0xFD)
 | |
| 			&& ((sbits32) (zSig + roundIncrement) < 0))
 | |
| 		    ) {
 | |
| 			float_raise(FPSCR_CAUSE_OVERFLOW | FPSCR_CAUSE_INEXACT);
 | |
| 			return packFloat32(zSign, 0xFF,
 | |
| 					   0) - (roundIncrement == 0);
 | |
| 		}
 | |
| 		if (zExp < 0) {
 | |
| 			isTiny = (zExp < -1)
 | |
| 			    || (zSig + roundIncrement < 0x80000000);
 | |
| 			shift32RightJamming(zSig, -zExp, &zSig);
 | |
| 			zExp = 0;
 | |
| 			roundBits = zSig & 0x7F;
 | |
| 			if (isTiny && roundBits)
 | |
| 				float_raise(FPSCR_CAUSE_UNDERFLOW);
 | |
| 		}
 | |
| 	}
 | |
| 	if (roundBits)
 | |
| 		float_raise(FPSCR_CAUSE_INEXACT);
 | |
| 	zSig = (zSig + roundIncrement) >> 7;
 | |
| 	zSig &= ~(((roundBits ^ 0x40) == 0) & roundNearestEven);
 | |
| 	if (zSig == 0)
 | |
| 		zExp = 0;
 | |
| 	return packFloat32(zSign, zExp, zSig);
 | |
| 
 | |
| }
 | |
| 
 | |
| static float32 normalizeRoundAndPackFloat32(flag zSign, int16 zExp, bits32 zSig)
 | |
| {
 | |
| 	int8 shiftCount;
 | |
| 
 | |
| 	shiftCount = countLeadingZeros32(zSig) - 1;
 | |
| 	return roundAndPackFloat32(zSign, zExp - shiftCount,
 | |
| 				   zSig << shiftCount);
 | |
| }
 | |
| 
 | |
| static float64 roundAndPackFloat64(flag zSign, int16 zExp, bits64 zSig)
 | |
| {
 | |
| 	flag roundNearestEven;
 | |
| 	int16 roundIncrement, roundBits;
 | |
| 	flag isTiny;
 | |
| 
 | |
| 	/* SH4 has only 2 rounding modes - round to nearest and round to zero */
 | |
| 	roundNearestEven = (float_rounding_mode() == FPSCR_RM_NEAREST);
 | |
| 	roundIncrement = 0x200;
 | |
| 	if (!roundNearestEven) {
 | |
| 		roundIncrement = 0;
 | |
| 	}
 | |
| 	roundBits = zSig & 0x3FF;
 | |
| 	if (0x7FD <= (bits16) zExp) {
 | |
| 		if ((0x7FD < zExp)
 | |
| 		    || ((zExp == 0x7FD)
 | |
| 			&& ((sbits64) (zSig + roundIncrement) < 0))
 | |
| 		    ) {
 | |
| 			float_raise(FPSCR_CAUSE_OVERFLOW | FPSCR_CAUSE_INEXACT);
 | |
| 			return packFloat64(zSign, 0x7FF,
 | |
| 					   0) - (roundIncrement == 0);
 | |
| 		}
 | |
| 		if (zExp < 0) {
 | |
| 			isTiny = (zExp < -1)
 | |
| 			    || (zSig + roundIncrement <
 | |
| 				LIT64(0x8000000000000000));
 | |
| 			shift64RightJamming(zSig, -zExp, &zSig);
 | |
| 			zExp = 0;
 | |
| 			roundBits = zSig & 0x3FF;
 | |
| 			if (isTiny && roundBits)
 | |
| 				float_raise(FPSCR_CAUSE_UNDERFLOW);
 | |
| 		}
 | |
| 	}
 | |
| 	if (roundBits)
 | |
| 		float_raise(FPSCR_CAUSE_INEXACT);
 | |
| 	zSig = (zSig + roundIncrement) >> 10;
 | |
| 	zSig &= ~(((roundBits ^ 0x200) == 0) & roundNearestEven);
 | |
| 	if (zSig == 0)
 | |
| 		zExp = 0;
 | |
| 	return packFloat64(zSign, zExp, zSig);
 | |
| 
 | |
| }
 | |
| 
 | |
| static float32 subFloat32Sigs(float32 a, float32 b, flag zSign)
 | |
| {
 | |
| 	int16 aExp, bExp, zExp;
 | |
| 	bits32 aSig, bSig, zSig;
 | |
| 	int16 expDiff;
 | |
| 
 | |
| 	aSig = extractFloat32Frac(a);
 | |
| 	aExp = extractFloat32Exp(a);
 | |
| 	bSig = extractFloat32Frac(b);
 | |
| 	bExp = extractFloat32Exp(b);
 | |
| 	expDiff = aExp - bExp;
 | |
| 	aSig <<= 7;
 | |
| 	bSig <<= 7;
 | |
| 	if (0 < expDiff)
 | |
| 		goto aExpBigger;
 | |
| 	if (expDiff < 0)
 | |
| 		goto bExpBigger;
 | |
| 	if (aExp == 0) {
 | |
| 		aExp = 1;
 | |
| 		bExp = 1;
 | |
| 	}
 | |
| 	if (bSig < aSig)
 | |
| 		goto aBigger;
 | |
| 	if (aSig < bSig)
 | |
| 		goto bBigger;
 | |
| 	return packFloat32(float_rounding_mode() == FPSCR_RM_ZERO, 0, 0);
 | |
|       bExpBigger:
 | |
| 	if (bExp == 0xFF) {
 | |
| 		return packFloat32(zSign ^ 1, 0xFF, 0);
 | |
| 	}
 | |
| 	if (aExp == 0) {
 | |
| 		++expDiff;
 | |
| 	} else {
 | |
| 		aSig |= 0x40000000;
 | |
| 	}
 | |
| 	shift32RightJamming(aSig, -expDiff, &aSig);
 | |
| 	bSig |= 0x40000000;
 | |
|       bBigger:
 | |
| 	zSig = bSig - aSig;
 | |
| 	zExp = bExp;
 | |
| 	zSign ^= 1;
 | |
| 	goto normalizeRoundAndPack;
 | |
|       aExpBigger:
 | |
| 	if (aExp == 0xFF) {
 | |
| 		return a;
 | |
| 	}
 | |
| 	if (bExp == 0) {
 | |
| 		--expDiff;
 | |
| 	} else {
 | |
| 		bSig |= 0x40000000;
 | |
| 	}
 | |
| 	shift32RightJamming(bSig, expDiff, &bSig);
 | |
| 	aSig |= 0x40000000;
 | |
|       aBigger:
 | |
| 	zSig = aSig - bSig;
 | |
| 	zExp = aExp;
 | |
|       normalizeRoundAndPack:
 | |
| 	--zExp;
 | |
| 	return normalizeRoundAndPackFloat32(zSign, zExp, zSig);
 | |
| 
 | |
| }
 | |
| 
 | |
| static float32 addFloat32Sigs(float32 a, float32 b, flag zSign)
 | |
| {
 | |
| 	int16 aExp, bExp, zExp;
 | |
| 	bits32 aSig, bSig, zSig;
 | |
| 	int16 expDiff;
 | |
| 
 | |
| 	aSig = extractFloat32Frac(a);
 | |
| 	aExp = extractFloat32Exp(a);
 | |
| 	bSig = extractFloat32Frac(b);
 | |
| 	bExp = extractFloat32Exp(b);
 | |
| 	expDiff = aExp - bExp;
 | |
| 	aSig <<= 6;
 | |
| 	bSig <<= 6;
 | |
| 	if (0 < expDiff) {
 | |
| 		if (aExp == 0xFF) {
 | |
| 			return a;
 | |
| 		}
 | |
| 		if (bExp == 0) {
 | |
| 			--expDiff;
 | |
| 		} else {
 | |
| 			bSig |= 0x20000000;
 | |
| 		}
 | |
| 		shift32RightJamming(bSig, expDiff, &bSig);
 | |
| 		zExp = aExp;
 | |
| 	} else if (expDiff < 0) {
 | |
| 		if (bExp == 0xFF) {
 | |
| 			return packFloat32(zSign, 0xFF, 0);
 | |
| 		}
 | |
| 		if (aExp == 0) {
 | |
| 			++expDiff;
 | |
| 		} else {
 | |
| 			aSig |= 0x20000000;
 | |
| 		}
 | |
| 		shift32RightJamming(aSig, -expDiff, &aSig);
 | |
| 		zExp = bExp;
 | |
| 	} else {
 | |
| 		if (aExp == 0xFF) {
 | |
| 			return a;
 | |
| 		}
 | |
| 		if (aExp == 0)
 | |
| 			return packFloat32(zSign, 0, (aSig + bSig) >> 6);
 | |
| 		zSig = 0x40000000 + aSig + bSig;
 | |
| 		zExp = aExp;
 | |
| 		goto roundAndPack;
 | |
| 	}
 | |
| 	aSig |= 0x20000000;
 | |
| 	zSig = (aSig + bSig) << 1;
 | |
| 	--zExp;
 | |
| 	if ((sbits32) zSig < 0) {
 | |
| 		zSig = aSig + bSig;
 | |
| 		++zExp;
 | |
| 	}
 | |
|       roundAndPack:
 | |
| 	return roundAndPackFloat32(zSign, zExp, zSig);
 | |
| 
 | |
| }
 | |
| 
 | |
| float64 float64_sub(float64 a, float64 b)
 | |
| {
 | |
| 	flag aSign, bSign;
 | |
| 
 | |
| 	aSign = extractFloat64Sign(a);
 | |
| 	bSign = extractFloat64Sign(b);
 | |
| 	if (aSign == bSign) {
 | |
| 		return subFloat64Sigs(a, b, aSign);
 | |
| 	} else {
 | |
| 		return addFloat64Sigs(a, b, aSign);
 | |
| 	}
 | |
| 
 | |
| }
 | |
| 
 | |
| float32 float32_sub(float32 a, float32 b)
 | |
| {
 | |
| 	flag aSign, bSign;
 | |
| 
 | |
| 	aSign = extractFloat32Sign(a);
 | |
| 	bSign = extractFloat32Sign(b);
 | |
| 	if (aSign == bSign) {
 | |
| 		return subFloat32Sigs(a, b, aSign);
 | |
| 	} else {
 | |
| 		return addFloat32Sigs(a, b, aSign);
 | |
| 	}
 | |
| 
 | |
| }
 | |
| 
 | |
| float32 float32_add(float32 a, float32 b)
 | |
| {
 | |
| 	flag aSign, bSign;
 | |
| 
 | |
| 	aSign = extractFloat32Sign(a);
 | |
| 	bSign = extractFloat32Sign(b);
 | |
| 	if (aSign == bSign) {
 | |
| 		return addFloat32Sigs(a, b, aSign);
 | |
| 	} else {
 | |
| 		return subFloat32Sigs(a, b, aSign);
 | |
| 	}
 | |
| 
 | |
| }
 | |
| 
 | |
| float64 float64_add(float64 a, float64 b)
 | |
| {
 | |
| 	flag aSign, bSign;
 | |
| 
 | |
| 	aSign = extractFloat64Sign(a);
 | |
| 	bSign = extractFloat64Sign(b);
 | |
| 	if (aSign == bSign) {
 | |
| 		return addFloat64Sigs(a, b, aSign);
 | |
| 	} else {
 | |
| 		return subFloat64Sigs(a, b, aSign);
 | |
| 	}
 | |
| }
 | |
| 
 | |
| static void
 | |
| normalizeFloat64Subnormal(bits64 aSig, int16 * zExpPtr, bits64 * zSigPtr)
 | |
| {
 | |
| 	int8 shiftCount;
 | |
| 
 | |
| 	shiftCount = countLeadingZeros64(aSig) - 11;
 | |
| 	*zSigPtr = aSig << shiftCount;
 | |
| 	*zExpPtr = 1 - shiftCount;
 | |
| }
 | |
| 
 | |
| void add128(bits64 a0, bits64 a1, bits64 b0, bits64 b1, bits64 * z0Ptr,
 | |
| 		   bits64 * z1Ptr)
 | |
| {
 | |
| 	bits64 z1;
 | |
| 
 | |
| 	z1 = a1 + b1;
 | |
| 	*z1Ptr = z1;
 | |
| 	*z0Ptr = a0 + b0 + (z1 < a1);
 | |
| }
 | |
| 
 | |
| void
 | |
| sub128(bits64 a0, bits64 a1, bits64 b0, bits64 b1, bits64 * z0Ptr,
 | |
|        bits64 * z1Ptr)
 | |
| {
 | |
| 	*z1Ptr = a1 - b1;
 | |
| 	*z0Ptr = a0 - b0 - (a1 < b1);
 | |
| }
 | |
| 
 | |
| static bits64 estimateDiv128To64(bits64 a0, bits64 a1, bits64 b)
 | |
| {
 | |
| 	bits64 b0, b1;
 | |
| 	bits64 rem0, rem1, term0, term1;
 | |
| 	bits64 z, tmp;
 | |
| 	if (b <= a0)
 | |
| 		return LIT64(0xFFFFFFFFFFFFFFFF);
 | |
| 	b0 = b >> 32;
 | |
| 	tmp = a0;
 | |
| 	do_div(tmp, b0);
 | |
| 
 | |
| 	z = (b0 << 32 <= a0) ? LIT64(0xFFFFFFFF00000000) : tmp << 32;
 | |
| 	mul64To128(b, z, &term0, &term1);
 | |
| 	sub128(a0, a1, term0, term1, &rem0, &rem1);
 | |
| 	while (((sbits64) rem0) < 0) {
 | |
| 		z -= LIT64(0x100000000);
 | |
| 		b1 = b << 32;
 | |
| 		add128(rem0, rem1, b0, b1, &rem0, &rem1);
 | |
| 	}
 | |
| 	rem0 = (rem0 << 32) | (rem1 >> 32);
 | |
| 	tmp = rem0;
 | |
| 	do_div(tmp, b0);
 | |
| 	z |= (b0 << 32 <= rem0) ? 0xFFFFFFFF : tmp;
 | |
| 	return z;
 | |
| }
 | |
| 
 | |
| void mul64To128(bits64 a, bits64 b, bits64 * z0Ptr, bits64 * z1Ptr)
 | |
| {
 | |
| 	bits32 aHigh, aLow, bHigh, bLow;
 | |
| 	bits64 z0, zMiddleA, zMiddleB, z1;
 | |
| 
 | |
| 	aLow = a;
 | |
| 	aHigh = a >> 32;
 | |
| 	bLow = b;
 | |
| 	bHigh = b >> 32;
 | |
| 	z1 = ((bits64) aLow) * bLow;
 | |
| 	zMiddleA = ((bits64) aLow) * bHigh;
 | |
| 	zMiddleB = ((bits64) aHigh) * bLow;
 | |
| 	z0 = ((bits64) aHigh) * bHigh;
 | |
| 	zMiddleA += zMiddleB;
 | |
| 	z0 += (((bits64) (zMiddleA < zMiddleB)) << 32) + (zMiddleA >> 32);
 | |
| 	zMiddleA <<= 32;
 | |
| 	z1 += zMiddleA;
 | |
| 	z0 += (z1 < zMiddleA);
 | |
| 	*z1Ptr = z1;
 | |
| 	*z0Ptr = z0;
 | |
| 
 | |
| }
 | |
| 
 | |
| static void normalizeFloat32Subnormal(bits32 aSig, int16 * zExpPtr,
 | |
| 				      bits32 * zSigPtr)
 | |
| {
 | |
| 	int8 shiftCount;
 | |
| 
 | |
| 	shiftCount = countLeadingZeros32(aSig) - 8;
 | |
| 	*zSigPtr = aSig << shiftCount;
 | |
| 	*zExpPtr = 1 - shiftCount;
 | |
| 
 | |
| }
 | |
| 
 | |
| float64 float64_div(float64 a, float64 b)
 | |
| {
 | |
| 	flag aSign, bSign, zSign;
 | |
| 	int16 aExp, bExp, zExp;
 | |
| 	bits64 aSig, bSig, zSig;
 | |
| 	bits64 rem0, rem1;
 | |
| 	bits64 term0, term1;
 | |
| 
 | |
| 	aSig = extractFloat64Frac(a);
 | |
| 	aExp = extractFloat64Exp(a);
 | |
| 	aSign = extractFloat64Sign(a);
 | |
| 	bSig = extractFloat64Frac(b);
 | |
| 	bExp = extractFloat64Exp(b);
 | |
| 	bSign = extractFloat64Sign(b);
 | |
| 	zSign = aSign ^ bSign;
 | |
| 	if (aExp == 0x7FF) {
 | |
| 		if (bExp == 0x7FF) {
 | |
| 		}
 | |
| 		return packFloat64(zSign, 0x7FF, 0);
 | |
| 	}
 | |
| 	if (bExp == 0x7FF) {
 | |
| 		return packFloat64(zSign, 0, 0);
 | |
| 	}
 | |
| 	if (bExp == 0) {
 | |
| 		if (bSig == 0) {
 | |
| 			if ((aExp | aSig) == 0) {
 | |
| 				float_raise(FPSCR_CAUSE_INVALID);
 | |
| 			}
 | |
| 			return packFloat64(zSign, 0x7FF, 0);
 | |
| 		}
 | |
| 		normalizeFloat64Subnormal(bSig, &bExp, &bSig);
 | |
| 	}
 | |
| 	if (aExp == 0) {
 | |
| 		if (aSig == 0)
 | |
| 			return packFloat64(zSign, 0, 0);
 | |
| 		normalizeFloat64Subnormal(aSig, &aExp, &aSig);
 | |
| 	}
 | |
| 	zExp = aExp - bExp + 0x3FD;
 | |
| 	aSig = (aSig | LIT64(0x0010000000000000)) << 10;
 | |
| 	bSig = (bSig | LIT64(0x0010000000000000)) << 11;
 | |
| 	if (bSig <= (aSig + aSig)) {
 | |
| 		aSig >>= 1;
 | |
| 		++zExp;
 | |
| 	}
 | |
| 	zSig = estimateDiv128To64(aSig, 0, bSig);
 | |
| 	if ((zSig & 0x1FF) <= 2) {
 | |
| 		mul64To128(bSig, zSig, &term0, &term1);
 | |
| 		sub128(aSig, 0, term0, term1, &rem0, &rem1);
 | |
| 		while ((sbits64) rem0 < 0) {
 | |
| 			--zSig;
 | |
| 			add128(rem0, rem1, 0, bSig, &rem0, &rem1);
 | |
| 		}
 | |
| 		zSig |= (rem1 != 0);
 | |
| 	}
 | |
| 	return roundAndPackFloat64(zSign, zExp, zSig);
 | |
| 
 | |
| }
 | |
| 
 | |
| float32 float32_div(float32 a, float32 b)
 | |
| {
 | |
| 	flag aSign, bSign, zSign;
 | |
| 	int16 aExp, bExp, zExp;
 | |
| 	bits32 aSig, bSig;
 | |
| 	uint64_t zSig;
 | |
| 
 | |
| 	aSig = extractFloat32Frac(a);
 | |
| 	aExp = extractFloat32Exp(a);
 | |
| 	aSign = extractFloat32Sign(a);
 | |
| 	bSig = extractFloat32Frac(b);
 | |
| 	bExp = extractFloat32Exp(b);
 | |
| 	bSign = extractFloat32Sign(b);
 | |
| 	zSign = aSign ^ bSign;
 | |
| 	if (aExp == 0xFF) {
 | |
| 		if (bExp == 0xFF) {
 | |
| 		}
 | |
| 		return packFloat32(zSign, 0xFF, 0);
 | |
| 	}
 | |
| 	if (bExp == 0xFF) {
 | |
| 		return packFloat32(zSign, 0, 0);
 | |
| 	}
 | |
| 	if (bExp == 0) {
 | |
| 		if (bSig == 0) {
 | |
| 			return packFloat32(zSign, 0xFF, 0);
 | |
| 		}
 | |
| 		normalizeFloat32Subnormal(bSig, &bExp, &bSig);
 | |
| 	}
 | |
| 	if (aExp == 0) {
 | |
| 		if (aSig == 0)
 | |
| 			return packFloat32(zSign, 0, 0);
 | |
| 		normalizeFloat32Subnormal(aSig, &aExp, &aSig);
 | |
| 	}
 | |
| 	zExp = aExp - bExp + 0x7D;
 | |
| 	aSig = (aSig | 0x00800000) << 7;
 | |
| 	bSig = (bSig | 0x00800000) << 8;
 | |
| 	if (bSig <= (aSig + aSig)) {
 | |
| 		aSig >>= 1;
 | |
| 		++zExp;
 | |
| 	}
 | |
| 	zSig = (((bits64) aSig) << 32);
 | |
| 	do_div(zSig, bSig);
 | |
| 
 | |
| 	if ((zSig & 0x3F) == 0) {
 | |
| 		zSig |= (((bits64) bSig) * zSig != ((bits64) aSig) << 32);
 | |
| 	}
 | |
| 	return roundAndPackFloat32(zSign, zExp, (bits32)zSig);
 | |
| 
 | |
| }
 | |
| 
 | |
| float32 float32_mul(float32 a, float32 b)
 | |
| {
 | |
| 	char aSign, bSign, zSign;
 | |
| 	int aExp, bExp, zExp;
 | |
| 	unsigned int aSig, bSig;
 | |
| 	unsigned long long zSig64;
 | |
| 	unsigned int zSig;
 | |
| 
 | |
| 	aSig = extractFloat32Frac(a);
 | |
| 	aExp = extractFloat32Exp(a);
 | |
| 	aSign = extractFloat32Sign(a);
 | |
| 	bSig = extractFloat32Frac(b);
 | |
| 	bExp = extractFloat32Exp(b);
 | |
| 	bSign = extractFloat32Sign(b);
 | |
| 	zSign = aSign ^ bSign;
 | |
| 	if (aExp == 0) {
 | |
| 		if (aSig == 0)
 | |
| 			return packFloat32(zSign, 0, 0);
 | |
| 		normalizeFloat32Subnormal(aSig, &aExp, &aSig);
 | |
| 	}
 | |
| 	if (bExp == 0) {
 | |
| 		if (bSig == 0)
 | |
| 			return packFloat32(zSign, 0, 0);
 | |
| 		normalizeFloat32Subnormal(bSig, &bExp, &bSig);
 | |
| 	}
 | |
| 	if ((bExp == 0xff && bSig == 0) || (aExp == 0xff && aSig == 0))
 | |
| 		return roundAndPackFloat32(zSign, 0xff, 0);
 | |
| 
 | |
| 	zExp = aExp + bExp - 0x7F;
 | |
| 	aSig = (aSig | 0x00800000) << 7;
 | |
| 	bSig = (bSig | 0x00800000) << 8;
 | |
| 	shift64RightJamming(((unsigned long long)aSig) * bSig, 32, &zSig64);
 | |
| 	zSig = zSig64;
 | |
| 	if (0 <= (signed int)(zSig << 1)) {
 | |
| 		zSig <<= 1;
 | |
| 		--zExp;
 | |
| 	}
 | |
| 	return roundAndPackFloat32(zSign, zExp, zSig);
 | |
| 
 | |
| }
 | |
| 
 | |
| float64 float64_mul(float64 a, float64 b)
 | |
| {
 | |
| 	char aSign, bSign, zSign;
 | |
| 	int aExp, bExp, zExp;
 | |
| 	unsigned long long int aSig, bSig, zSig0, zSig1;
 | |
| 
 | |
| 	aSig = extractFloat64Frac(a);
 | |
| 	aExp = extractFloat64Exp(a);
 | |
| 	aSign = extractFloat64Sign(a);
 | |
| 	bSig = extractFloat64Frac(b);
 | |
| 	bExp = extractFloat64Exp(b);
 | |
| 	bSign = extractFloat64Sign(b);
 | |
| 	zSign = aSign ^ bSign;
 | |
| 
 | |
| 	if (aExp == 0) {
 | |
| 		if (aSig == 0)
 | |
| 			return packFloat64(zSign, 0, 0);
 | |
| 		normalizeFloat64Subnormal(aSig, &aExp, &aSig);
 | |
| 	}
 | |
| 	if (bExp == 0) {
 | |
| 		if (bSig == 0)
 | |
| 			return packFloat64(zSign, 0, 0);
 | |
| 		normalizeFloat64Subnormal(bSig, &bExp, &bSig);
 | |
| 	}
 | |
| 	if ((aExp == 0x7ff && aSig == 0) || (bExp == 0x7ff && bSig == 0))
 | |
| 		return roundAndPackFloat64(zSign, 0x7ff, 0);
 | |
| 
 | |
| 	zExp = aExp + bExp - 0x3FF;
 | |
| 	aSig = (aSig | 0x0010000000000000LL) << 10;
 | |
| 	bSig = (bSig | 0x0010000000000000LL) << 11;
 | |
| 	mul64To128(aSig, bSig, &zSig0, &zSig1);
 | |
| 	zSig0 |= (zSig1 != 0);
 | |
| 	if (0 <= (signed long long int)(zSig0 << 1)) {
 | |
| 		zSig0 <<= 1;
 | |
| 		--zExp;
 | |
| 	}
 | |
| 	return roundAndPackFloat64(zSign, zExp, zSig0);
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * -------------------------------------------------------------------------------
 | |
|  *  Returns the result of converting the double-precision floating-point value
 | |
|  *  `a' to the single-precision floating-point format.  The conversion is
 | |
|  *  performed according to the IEC/IEEE Standard for Binary Floating-point
 | |
|  *  Arithmetic.
 | |
|  *  -------------------------------------------------------------------------------
 | |
|  *  */
 | |
| float32 float64_to_float32(float64 a)
 | |
| {
 | |
|     flag aSign;
 | |
|     int16 aExp;
 | |
|     bits64 aSig;
 | |
|     bits32 zSig;
 | |
| 
 | |
|     aSig = extractFloat64Frac( a );
 | |
|     aExp = extractFloat64Exp( a );
 | |
|     aSign = extractFloat64Sign( a );
 | |
| 
 | |
|     shift64RightJamming( aSig, 22, &aSig );
 | |
|     zSig = aSig;
 | |
|     if ( aExp || zSig ) {
 | |
|         zSig |= 0x40000000;
 | |
|         aExp -= 0x381;
 | |
|     }
 | |
|     return roundAndPackFloat32(aSign, aExp, zSig);
 | |
| }
 |