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-rw-r--r--arch/sh/kernel/cpu/sh4/softfloat.c892
1 files changed, 892 insertions, 0 deletions
diff --git a/arch/sh/kernel/cpu/sh4/softfloat.c b/arch/sh/kernel/cpu/sh4/softfloat.c
new file mode 100644
index 000000000000..7b2d337ee412
--- /dev/null
+++ b/arch/sh/kernel/cpu/sh4/softfloat.c
@@ -0,0 +1,892 @@
+/*
+ * 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 <asm/cpu/fpu.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 */
+
+inline bits64 extractFloat64Frac(float64 a);
+inline flag extractFloat64Sign(float64 a);
+inline int16 extractFloat64Exp(float64 a);
+inline int16 extractFloat32Exp(float32 a);
+inline flag extractFloat32Sign(float32 a);
+inline bits32 extractFloat32Frac(float32 a);
+inline float64 packFloat64(flag zSign, int16 zExp, bits64 zSig);
+inline void shift64RightJamming(bits64 a, int16 count, bits64 * zPtr);
+inline float32 packFloat32(flag zSign, int16 zExp, bits32 zSig);
+inline 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);
+inline void add128(bits64 a0, bits64 a1, bits64 b0, bits64 b1, bits64 * z0Ptr,
+ bits64 * z1Ptr);
+inline void sub128(bits64 a0, bits64 a1, bits64 b0, bits64 b1, bits64 * z0Ptr,
+ bits64 * z1Ptr);
+inline 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);
+
+inline bits64 extractFloat64Frac(float64 a)
+{
+ return a & LIT64(0x000FFFFFFFFFFFFF);
+}
+
+inline flag extractFloat64Sign(float64 a)
+{
+ return a >> 63;
+}
+
+inline int16 extractFloat64Exp(float64 a)
+{
+ return (a >> 52) & 0x7FF;
+}
+
+inline int16 extractFloat32Exp(float32 a)
+{
+ return (a >> 23) & 0xFF;
+}
+
+inline flag extractFloat32Sign(float32 a)
+{
+ return a >> 31;
+}
+
+inline bits32 extractFloat32Frac(float32 a)
+{
+ return a & 0x007FFFFF;
+}
+
+inline float64 packFloat64(flag zSign, int16 zExp, bits64 zSig)
+{
+ return (((bits64) zSign) << 63) + (((bits64) zExp) << 52) + zSig;
+}
+
+inline 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;
+ bits64 aSig, bSig, zSig;
+ int16 expDiff;
+
+ 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);
+
+}
+
+inline float32 packFloat32(flag zSign, int16 zExp, bits32 zSig)
+{
+ return (((bits32) zSign) << 31) + (((bits32) zExp) << 23) + zSig;
+}
+
+inline 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;
+}
+
+inline 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);
+}
+
+inline 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;
+ if (b <= a0)
+ return LIT64(0xFFFFFFFFFFFFFFFF);
+ b0 = b >> 32;
+ z = (b0 << 32 <= a0) ? LIT64(0xFFFFFFFF00000000) : (a0 / b0) << 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);
+ z |= (b0 << 32 <= rem0) ? 0xFFFFFFFF : rem0 / b0;
+ return z;
+}
+
+inline 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, 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) / bSig;
+ if ((zSig & 0x3F) == 0) {
+ zSig |= (((bits64) bSig) * zSig != ((bits64) aSig) << 32);
+ }
+ return roundAndPackFloat32(zSign, zExp, 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);
+}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.