aboutsummaryrefslogtreecommitdiff
path: root/sysdeps/powerpc/q_addsub.c
diff options
context:
space:
mode:
Diffstat (limited to 'sysdeps/powerpc/q_addsub.c')
-rw-r--r--sysdeps/powerpc/q_addsub.c549
1 files changed, 0 insertions, 549 deletions
diff --git a/sysdeps/powerpc/q_addsub.c b/sysdeps/powerpc/q_addsub.c
deleted file mode 100644
index e4ef6d8165..0000000000
--- a/sysdeps/powerpc/q_addsub.c
+++ /dev/null
@@ -1,549 +0,0 @@
-/* Add or subtract two 128-bit floating point values. C prototype.
- Copyright (C) 1997 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
-
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Library General Public License as
- published by the Free Software Foundation; either version 2 of the
- License, or (at your option) any later version.
-
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Library General Public License for more details.
-
- You should have received a copy of the GNU Library General Public
- License along with the GNU C Library; see the file COPYING.LIB. If not,
- write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA. */
-
-#include <quad_float.h>
-
-/* Add 'a' to 'b' and put the result in 'result', but treat a[0]=axx,
- b[0]=bxx. bxx differs from b[0] only in the high bit, similarly axx. */
-/* Exceptions to raise:
- - Invalid (SNaN)
- - Invalid (Inf-Inf)
- - Overflow
- - Underflow
- - Inexact
- */
-
-/* Handle cases where exponent of a or b is maximum. */
-static void
-handle_max_exponent(unsigned result[4],
- const unsigned a[4], const unsigned b[4],
- const unsigned axx, /* Treat as a[0]. */
- const unsigned bxx, /* Treat as b[0]. */
- const unsigned ax, /* axx >> 16 & 0x7fff. */
- const unsigned bx) /* bxx >> 16 & 0x7fff. */
-{
- int ax_ismax, bx_ismax;
- unsigned a1,a2,a3, b1,b2,b3;
- int a_zeromant, b_zeromant;
-
- ax_ismax = ax == 0x7fff;
- bx_ismax = bx == 0x7fff;
-
- assert(ax_ismax || bx_ismax);
-
- a1 = a[1]; a2 = a[2]; a3 = a[3];
- b1 = b[1]; b2 = b[2]; b3 = b[3];
-
- a_zeromant = (axx & 0xffff | a1 | a2 | a3) == 0;
- b_zeromant = (bxx & 0xffff | b1 | b2 | b3) == 0;
-
- /* Deal with SNaNs. */
- if ( ax_ismax && !a_zeromant && (axx & 0x8000) == 0
- || bx_ismax && !b_zeromant && (bxx & 0x8000) == 0)
- {
- set_fpscr_bit(FPSCR_VXSNAN);
- axx |= 0x8000; /* Demote the SNaN to a QNaN (whichever of */
- bxx |= 0x8000; /* a or b it was). */
- }
- /* Deal with Inf-Inf. */
- else if (a_zeromant && b_zeromant && (axx ^ bxx) == 0x80000000)
- {
- set_fpscr_bit(FPSCR_VXISI);
- bxx |= 0x8000; /* Return an appropriate QNaN. */
- }
-
- /* Return the lexicographically larger of a or b, ignoring the sign
- bits. */
- if ((axx & 0x7fffffff) > (bxx & 0x7fffffff)) goto return_a;
- else if ((axx & 0x7fffffff) < (bxx & 0x7fffffff)) goto return_b;
- else if (a1 > b1) goto return_a;
- else if (a1 < b1) goto return_b;
- else if (a2 > b2) goto return_a;
- else if (a2 < b2) goto return_b;
- else if (a3 > b3) goto return_a; /* I've clearly been writing too */
- else if (a3 < b3) goto return_b; /* much Fortran... */
-
- /* If they are equal except for the sign bits, return 'b'. */
-
-return_b:
- result[0] = bxx; result[1] = b1; result[2] = b2; result[3] = b3;
- return;
-
-return_a:
- result[0] = axx; result[1] = a1; result[2] = a2; result[3] = a3;
- return;
-}
-
-/* Renormalise and output a FP number. */
-static void
-renormalise_value(unsigned result[4],
- const unsigned axx,
- unsigned ax,
- unsigned r0,
- unsigned r1,
- unsigned r2,
- unsigned r3)
-{
- int rshift;
- if (r0 != 0 || cntlzw(a1) < 16 || 32 > ax-1)
- {
- rshift = cntlzw(r0)-15 + (-(cntlzw(r0) >> 5) & cntlzw(a1));
- assert(rshift < 32);
- if (rshift > ax-1)
- {
- ax--;
- rshift = ax;
- }
-
- result[0] = (axx & 0x80000000
- | ax-rshift << 16
- | r0 << rshift & 0xffff
- | a1 >> 32-rshift & 0xffff);
- result[1] = a1 << rshift | a2 >> 32-rshift;
- result[2] = a2 << rshift | a3 >> 32-rshift;
- result[3] = a3 << rshift;
- return;
- }
- result[3] = 0;
- /* Special case for zero. */
- if (a1 == 0 && a2 == 0 && a3 == 0)
- {
- result[0] = axx & 0x80000000;
- result[1] = result[2] = 0;
- return;
- }
- while (a1 != 0 && cntlzw(a2) >= 16 && 64 <= ax-1)
- {
- ax -= 32;
- a1 = a2; a2 = a3; a3 = 0;
- }
- rshift = cntlzw(a1)-15 + (-(cntlzw(a1) >> 5) & cntlzw(a2));
- assert(rshift < 32);
- if (rshift > ax-1-32)
- {
- ax--;
- rshift = ax-32;
- }
-
- result[0] = (axx & 0x80000000
- | ax-rshift-32 << 16
- | a1 << rshift & 0xffff
- | a2 >> 32-rshift & 0xffff);
- result[1] = a2 << rshift | a3 >> 32-rshift;
- result[2] = a3 << rshift;
- return;
-}
-
-/* Handle the case where one or both numbers are denormalised or zero.
- This case almost never happens, so we don't slow the main code
- with it. */
-static void
-handle_min_exponent(unsigned result[4],
- const unsigned a[4], const unsigned b[4],
- const unsigned axx, /* Treat as a[0]. */
- const unsigned bxx, /* Treat as b[0]. */
- const unsigned ax, /* axx >> 16 & 0x7fff. */
- const unsigned bx) /* bxx >> 16 & 0x7fff. */
-{
- int ax_denorm, bx_denorm;
- unsigned a1,a2,a3, b1,b2,b3;
- int a_zeromant, b_zeromant;
-
- ax_denorm = ax == 0;
- bx_denorm = bx == 0;
-
- assert(ax_denorm || bx_denorm);
-
- a1 = a[1]; a2 = a[2]; a3 = a[3];
- b1 = b[1]; b2 = b[2]; b3 = b[3];
-
-
-}
-
-/* Add a+b+cin modulo 2^32, put result in 'r' and carry in 'cout'. */
-#define addc(r,cout,a,b,cin) \
- do { \
- unsigned long long addc_tmp = (a)+(b)+(cin);
- (cout) = addc_tmp >> 32;
- (r) = addc_tmp;
- }
-
-/* Calculate a+~b+cin modulo 2^32, put result in 'r' and carry in 'cout'. */
-#define subc(r,cout,a,b,cin) \
- do { \
- unsigned long long addc_tmp = (a)-(b)+(cin)-1;
- (cout) = addc_tmp >> 63;
- (r) = addc_tmp;
- }
-
-/* Handle the case where both exponents are the same. This requires quite
- a different algorithm than the general case. */
-static void
-handle_equal_exponents(unsigned result[4],
- const unsigned a[4], const unsigned b[4],
- const unsigned axx, /* Treat as a[0]. */
- const unsigned bxx, /* Treat as b[0]. */
- unsigned ax) /* [ab]xx >> 16 & 0x7fff. */
-{
- unsigned a1,a2,a3, b1,b2,b3;
- int roundmode;
- unsigned carry, r0;
-
- a1 = a[1]; a2 = a[2]; a3 = a[3];
- b1 = b[1]; b2 = b[2]; b3 = b[3];
-
- if ((int)(axx ^ bxx) >= 0)
- {
- int roundmode;
-
- /* Adding. */
- roundmode = fegetround();
-
- /* What about overflow? */
- if (ax == 0x7ffe)
- {
- /* Oh no! Too big! */
- /* Result:
- rounding result
- -------- ------
- nearest return Inf with sign of a,b
- zero return nearest possible non-Inf value with
- sign of a,b
- +Inf return +Inf if a,b>0, otherwise return
- value just before -Inf.
- -Inf return +Inf if a,b>0, otherwise return
- value just before -Inf.
- */
- set_fpscr_bit(FPSCR_OX);
- /* Overflow always produces inexact result. */
- set_fpscr_bit(FPSCR_XX);
-
- if ( roundmode == FE_TONEAREST
- || roundmode == FE_UPWARD && (int)axx >= 0
- || roundmode == FE_DOWNWARD && (int)axx < 0)
- {
- result[3] = result[2] = result[1] = 0;
- result[0] = axx & 0xffff0000 | 0x7fff0000;
- }
- else
- {
- result[3] = result[2] = result[1] = 0xffffffff;
- result[0] = axx & 0xfffe0000 | 0x7ffeffff;
- }
- return;
- }
-
- /* We need to worry about rounding/inexact here. Do it like this: */
- if (a3 + b3 & 1)
- {
- /* Need to round. Upwards? */
- set_fpscr_bit(FPSCR_XX);
- carry = ( roundmode == FE_NEAREST && (a3 + b3 & 2) != 0
- || roundmode == FE_UPWARD && (int)axx >= 0
- || roundmode == FE_DOWNWARD && (int)axx < 0);
- }
- else
- carry = 0; /* Result will be exact. */
-
- /* Perform the addition. */
- addc(a3,carry,a3,b3,carry);
- addc(a2,carry,a2,b2,carry);
- addc(a1,carry,a1,b1,carry);
- r0 = (axx & 0xffff) + (bxx & 0xffff) + carry;
-
- /* Shift right by 1. */
- result[3] = a3 >> 1 | a2 << 31;
- result[2] = a2 >> 1 | a1 << 31;
- result[1] = a1 >> 1 | r0 << 31;
- /* Exponent of result is exponent of inputs plus 1.
- Sign of result is common sign of inputs. */
- result[0] = r0 >> 1 & 0xffff | axx + 0x10000 & 0xffff0000;
- }
- else
- {
- /* Subtracting. */
-
- /* Perform the subtraction, a-b. */
- subc(a3,carry,a3,b3,0);
- subc(a2,carry,a2,b2,carry);
- subc(a1,carry,a1,b1,carry);
- subc(r0,carry,a0&0xffff,b0&0xffff,carry);
-
- /* Maybe we should have calculated b-a... */
- if (carry)
- {
- subc(a3,carry,0,a3,0);
- subc(a2,carry,0,a2,carry);
- subc(a1,carry,0,a1,carry);
- subc(r0,carry,0,r0,carry);
- axx ^= 0x80000000;
- }
-
- renormalise_value(result, axx, ax, r0, a1, a2, a3);
- }
-}
-
-
-static void
-add(unsigned result[4], const unsigned a[4], const unsigned b[4],
- unsigned axx, unsigned bxx)
-{
- int ax, bx, diff, carry;
- unsigned a0,a1,a2,a3, b0,b1,b2,b3,b4, sdiff;
-
- ax = axx >> 16 & 0x7fff;
- bx = bxx >> 16 & 0x7fff;
-
- /* Deal with NaNs and Inf. */
- if (ax == 0x7fff || bx == 0x7fff)
- {
- handle_max_exponent(result, a, b, axx, bxx, ax, bx);
- return;
- }
- /* Deal with denorms and zero. */
- if (ax == 0 || bx == 0)
- {
- handle_min_exponent(result, a, b, axx, bxx, ax, bx);
- return;
- }
- /* Finally, one special case, when both exponents are equal. */
- if (ax == bx)
- {
- handle_equal_exponents(result, a, b, axx, bxx, ax);
- return;
- }
-
- sdiff = axx ^ bxx;
- /* Swap a and b if b has a larger magnitude than a, so that a will have
- the larger magnitude. */
- if (ax < bx)
- {
- const unsigned *t;
- t = b; b = a; a = t;
- diff = bx - ax;
- ax = bx;
- axx = bxx;
- }
- else
- diff = ax - bx;
-
- a0 = a[0] & 0xffff | 0x10000; a1 = a[1]; a2 = a[2]; a3 = a[3];
- b0 = b[0] & 0xffff | 0x10000; b1 = b[1]; b2 = b[2]; b3 = b[3];
- if (diff < 32)
- {
- b4 = b3 << 32-diff;
- b3 = b3 >> diff | b2 << 32-biff;
- b2 = b2 >> diff | b1 << 32-diff;
- b1 = b1 >> diff | b0 << 32-diff;
- b0 = b0 >> diff;
- }
- else if (diff < 64)
- {
- diff -= 32;
- b4 = b3 & 1 | b3 >> (diff == 32) | b2 << 32-biff;
- b3 = b2 >> diff | b1 << 32-diff;
- b2 = b1 >> diff | b0 << 32-diff;
- b1 = b0 >> diff;
- b0 = 0;
- }
- else if (diff < 96)
- {
- b4 = b2 | b3 | b1 << 32-diff;
- b3 = b1 >> diff | b0 << 32-diff;
- b2 = b0 >> diff;
- b1 = b0 = 0;
- }
- else if (diff < 128)
- {
- b4 = b1 | b2 | b3 | b0 << 32-diff;
- b3 = b0 >> diff;
- b2 = b1 = b0 = 0;
- }
- else
- {
- b4 = b0|b1|b2|b3;
- b3 = b2 = b1 = b0 = 0;
- }
-
- /* Now, two cases: one for addition, one for subtraction. */
- if ((int)sdiff >= 0)
- {
- /* Addition. */
-
- /*
-
- /* Perform the addition. */
- addc(a3,carry,a3,b3,0);
- addc(a2,carry,a2,b2,carry);
- addc(a1,carry,a1,b1,carry);
- addc(a0,carry,a0,b0,carry);
-
-
-
- if (a0 & 0x20000)
- {
- /* Need to renormalise by shifting right. */
- /* Shift right by 1. */
- b4 = b4 | a3 << 31;
- a3 = a3 >> 1 | a2 << 31;
- a2 = a2 >> 1 | a1 << 31;
- result[1] = a1 >> 1 | r0 << 31;
- /* Exponent of result is exponent of inputs plus 1.
- Sign of result is common sign of inputs. */
- result[0] = r0 >> 1 & 0xffff | axx + 0x10000 & 0xffff0000;
- }
-
-
- }
- else
- {
- /* Subtraction. */
-
- }
-}
-
-/* Add the absolute values of two 128-bit floating point values,
- give the result the sign of one of them. The only exception this
- can raise is for SNaN. */
-static void
-aadd(unsigned result[4], const unsigned a[4], const unsigned b[4])
-{
- unsigned ax, bx, xd;
- const unsigned *sml;
- unsigned t0,t1,t2,t3,tx, s0,s1,s2,s3,s4, carry;
- int rmode, xdelta, shift;
-
- ax = a[0] >> 16 & 0x7fff;
- bx = b[0] >> 16 & 0x7fff;
-
- /* Deal with . */
- if (ax == 0x7fff)
- {
- t0 = a[0]; t1 = a[1]; t2 = a[2]; t3 = a[3];
- /* Check for SNaN. */
- if ((t0 & 0x8000) == 0
- && (t0 & 0x7fff | t1 | t2 | t3) != 0)
- set_fpscr_bit(FPSCR_VXSNAN);
- /* Return b. */
- result[0] = t0; result[1] = t1; result[2] = t2; result[3] = t3;
- return;
- }
- /* Deal with b==Inf or b==NaN. */
- if (bx == 0x7fff)
- {
- t0 = b[0]; t1 = b[1]; t2 = b[2]; t3 = b[3];
- /* Check for SNaN. */
- if ((t0 & 0x8000) == 0
- && (t0 & 0x7fff | t1 | t2 | t3) != 0)
- set_fpscr_bit(FPSCR_VXSNAN);
- /* Return b. */
- result[0] = t0; result[1] = t1; result[2] = t2; result[3] = t3;
- return;
- }
-
- /* Choose the larger of the two to be 't', and the smaller to be 's'. */
- if (ax > bx)
- {
- t0 = a[0] & 0xffff | (ax != 0) << 16;
- t1 = a[1]; t2 = a[2]; t3 = a[3]; tx = ax;
- s0 = b[0] & 0xffff | (bx != 0) << 16;
- s1 = b[1]; s2 = b[2]; s3 = b[3];
- xd = ax-bx;
- }
- else
- {
- t0 = b[0] & 0xffff | (bx != 0) << 16;
- t1 = b[1]; t2 = b[2]; t3 = b[3]; tx = bx;
- s0 = a[0] & 0xffff | (ax != 0) << 16;
- s1 = a[1]; s2 = a[2]; s3 = a[3];
- sml = a;
- xd = bx-ax;
- }
-
- /* Shift 's2' right by 'xd' bits. */
- switch (xd >> 5)
- {
- case 0:
- s4 = 0;
- break;
- case 1:
- s4 = s3; s3 = s2; s2 = s1; s1 = s0; s0 = 0;
- break;
- case 2:
- s4 = s2 | s3 != 0;
- s3 = s1; s2 = s0; s1 = s0 = 0;
- break;
- case 3:
- s4 = s1 | (s3|s2) != 0;
- s3 = s0; s2 = s1 = s0 = 0;
- break;
- default:
- s4 = s0 | (s3|s2|s1) != 0;
- s3 = s2 = s1 = s0 = 0;
- }
- xd = xd & 0x1f;
- if (xd != 0)
- {
- s4 = s4 >> xd | (s4 << 32-xd) != 0 | s3 << 32-xd;
- s3 = s3 >> xd | s2 << 32-xd;
- s2 = s2 >> xd | s1 << 32-xd;
- s1 = s1 >> xd | s0 << 32-xd;
- s0 = s0 >> xd;
- }
-
- /* Do the addition. */
-#define addc(r,cout,a,b,cin) \
- do { \
- unsigned long long addc_tmp = (a)+(b)+(cin);
- (cout) = addc_tmp >> 32;
- (r) = addc_tmp;
- }
- addc(t3,carry,t3,s3,0);
- addc(t2,carry,t2,s2,carry);
- addc(t1,carry,t1,s1,carry);
- t0 = t0 + s0 + carry;
-
- /* Renormalise. */
- xdelta = 15-cntlzw(t0);
- if (tx + xdelta <= 0x7fff)
- shift = xdelta;
- else
- {
- }
-}
-
-/* Add two 128-bit floating point values. */
-void
-__q_add(unsigned result[4], const unsigned a[4], const unsigned b[4])
-{
- if ((a[0] ^ b[0]) >= 0)
- aadd(result, a, b);
- else
- asubtract(result, a, b);
-}
-
-/* Subtract two 128-bit floating point values. */
-void
-__q_sub(unsigned result[4], const unsigned a[4], const unsigned b[4])
-{
- if ((a[0] ^ b[0]) < 0)
- aadd(result, a, b);
- else
- asubtract(result, a, b);
-}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-11 23:46:06 +0000