Index: gcc/gmp/mpn/x86/pentium/mmx/mul_1.asm |
diff --git a/gcc/gmp/mpn/x86/pentium/mmx/mul_1.asm b/gcc/gmp/mpn/x86/pentium/mmx/mul_1.asm |
deleted file mode 100644 |
index b9fe77ed0743f6af2989aedba9720e56c74da3cc..0000000000000000000000000000000000000000 |
--- a/gcc/gmp/mpn/x86/pentium/mmx/mul_1.asm |
+++ /dev/null |
@@ -1,360 +0,0 @@ |
-dnl Intel Pentium MMX mpn_mul_1 -- mpn by limb multiplication. |
- |
-dnl Copyright 2000, 2001, 2002 Free Software Foundation, Inc. |
-dnl |
-dnl This file is part of the GNU MP Library. |
-dnl |
-dnl The GNU MP Library is free software; you can redistribute it and/or |
-dnl modify it under the terms of the GNU Lesser General Public License as |
-dnl published by the Free Software Foundation; either version 3 of the |
-dnl License, or (at your option) any later version. |
-dnl |
-dnl The GNU MP Library is distributed in the hope that it will be useful, |
-dnl but WITHOUT ANY WARRANTY; without even the implied warranty of |
-dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
-dnl Lesser General Public License for more details. |
-dnl |
-dnl You should have received a copy of the GNU Lesser General Public License |
-dnl along with the GNU MP Library. If not, see http://www.gnu.org/licenses/. |
- |
-include(`../config.m4') |
- |
- |
-C cycles/limb |
-C P5: 12.0 for 32-bit multiplier |
-C 7.0 for 16-bit multiplier |
- |
- |
-C mp_limb_t mpn_mul_1 (mp_ptr dst, mp_srcptr src, mp_size_t size, |
-C mp_limb_t multiplier); |
-C |
-C When the multiplier is 16 bits some special case MMX code is used. Small |
-C multipliers might arise reasonably often from mpz_mul_ui etc. If the size |
-C is odd there's roughly a 5 cycle penalty, so times for say size==7 and |
-C size==8 end up being quite close. If src isn't aligned to an 8 byte |
-C boundary then one limb is processed separately with roughly a 5 cycle |
-C penalty, so in that case it's say size==8 and size==9 which are close. |
-C |
-C Alternatives: |
-C |
-C MMX is not believed to be of any use for 32-bit multipliers, since for |
-C instance the current method would just have to be more or less duplicated |
-C for the high and low halves of the multiplier, and would probably |
-C therefore run at about 14 cycles, which is slower than the plain integer |
-C at 12. |
-C |
-C Adding the high and low MMX products using integer code seems best. An |
-C attempt at using paddd and carry bit propagation with pcmpgtd didn't give |
-C any joy. Perhaps something could be done keeping the values signed and |
-C thereby avoiding adjustments to make pcmpgtd into an unsigned compare, or |
-C perhaps not. |
-C |
-C Future: |
-C |
-C An mpn_mul_1c entrypoint would need a double carry out of the low result |
-C limb in the 16-bit code, unless it could be assumed the carry fits in 16 |
-C bits, possibly as carry<multiplier, this being true of a big calculation |
-C done piece by piece. But let's worry about that if/when mul_1c is |
-C actually used. |
- |
-defframe(PARAM_MULTIPLIER,16) |
-defframe(PARAM_SIZE, 12) |
-defframe(PARAM_SRC, 8) |
-defframe(PARAM_DST, 4) |
- |
- TEXT |
- |
- ALIGN(8) |
-PROLOGUE(mpn_mul_1) |
-deflit(`FRAME',0) |
- |
- movl PARAM_SIZE, %ecx |
- movl PARAM_SRC, %edx |
- |
- cmpl $1, %ecx |
- jne L(two_or_more) |
- |
- C one limb only |
- |
- movl PARAM_MULTIPLIER, %eax |
- movl PARAM_DST, %ecx |
- |
- mull (%edx) |
- |
- movl %eax, (%ecx) |
- movl %edx, %eax |
- |
- ret |
- |
- |
-L(two_or_more): |
- C eax size |
- C ebx |
- C ecx carry |
- C edx |
- C esi src |
- C edi |
- C ebp |
- |
- pushl %esi FRAME_pushl() |
- pushl %edi FRAME_pushl() |
- |
- movl %edx, %esi C src |
- movl PARAM_DST, %edi |
- |
- movl PARAM_MULTIPLIER, %eax |
- pushl %ebx FRAME_pushl() |
- |
- leal (%esi,%ecx,4), %esi C src end |
- leal (%edi,%ecx,4), %edi C dst end |
- |
- negl %ecx C -size |
- |
- pushl %ebp FRAME_pushl() |
- cmpl $65536, %eax |
- |
- jb L(small) |
- |
- |
-L(big): |
- xorl %ebx, %ebx C carry limb |
- sarl %ecx C -size/2 |
- |
- jnc L(top) C with carry flag clear |
- |
- |
- C size was odd, process one limb separately |
- |
- mull 4(%esi,%ecx,8) C m * src[0] |
- |
- movl %eax, 4(%edi,%ecx,8) |
- incl %ecx |
- |
- orl %edx, %ebx C carry limb, and clear carry flag |
- |
- |
-L(top): |
- C eax |
- C ebx carry |
- C ecx counter, negative |
- C edx |
- C esi src end |
- C edi dst end |
- C ebp (scratch carry) |
- |
- adcl $0, %ebx |
- movl (%esi,%ecx,8), %eax |
- |
- mull PARAM_MULTIPLIER |
- |
- movl %edx, %ebp |
- addl %eax, %ebx |
- |
- adcl $0, %ebp |
- movl 4(%esi,%ecx,8), %eax |
- |
- mull PARAM_MULTIPLIER |
- |
- movl %ebx, (%edi,%ecx,8) |
- addl %ebp, %eax |
- |
- movl %eax, 4(%edi,%ecx,8) |
- incl %ecx |
- |
- movl %edx, %ebx |
- jnz L(top) |
- |
- |
- adcl $0, %ebx |
- popl %ebp |
- |
- movl %ebx, %eax |
- popl %ebx |
- |
- popl %edi |
- popl %esi |
- |
- ret |
- |
- |
-L(small): |
- C Special case for 16-bit multiplier. |
- C |
- C eax multiplier |
- C ebx |
- C ecx -size |
- C edx src |
- C esi src end |
- C edi dst end |
- C ebp multiplier |
- |
- C size<3 not supported here. At size==3 we're already a couple of |
- C cycles faster, so there's no threshold as such, just use the MMX |
- C as soon as possible. |
- |
- cmpl $-3, %ecx |
- ja L(big) |
- |
- movd %eax, %mm7 C m |
- pxor %mm6, %mm6 C initial carry word |
- |
- punpcklwd %mm7, %mm7 C m replicated 2 times |
- addl $2, %ecx C -size+2 |
- |
- punpckldq %mm7, %mm7 C m replicated 4 times |
- andl $4, %edx C test alignment, clear carry flag |
- |
- movq %mm7, %mm0 C m |
- jz L(small_entry) |
- |
- |
- C Source is unaligned, process one limb separately. |
- C |
- C Plain integer code is used here, since it's smaller and is about |
- C the same 13 cycles as an mmx block would be. |
- C |
- C An "addl $1,%ecx" doesn't clear the carry flag when size==3, hence |
- C the use of separate incl and orl. |
- |
- mull -8(%esi,%ecx,4) C m * src[0] |
- |
- movl %eax, -8(%edi,%ecx,4) C dst[0] |
- incl %ecx C one limb processed |
- |
- movd %edx, %mm6 C initial carry |
- |
- orl %eax, %eax C clear carry flag |
- jmp L(small_entry) |
- |
- |
-C The scheduling here is quite tricky, since so many instructions have |
-C pairing restrictions. In particular the js won't pair with a movd, and |
-C can't be paired with an adc since it wants flags from the inc, so |
-C instructions are rotated to the top of the loop to find somewhere useful |
-C for it. |
-C |
-C Trouble has been taken to avoid overlapping successive loop iterations, |
-C since that would greatly increase the size of the startup and finishup |
-C code. Actually there's probably not much advantage to be had from |
-C overlapping anyway, since the difficulties are mostly with pairing, not |
-C with latencies as such. |
-C |
-C In the comments x represents the src data and m the multiplier (16 |
-C bits, but replicated 4 times). |
-C |
-C The m signs calculated in %mm3 are a loop invariant and could be held in |
-C say %mm5, but that would save only one instruction and hence be no faster. |
- |
-L(small_top): |
- C eax l.low, then l.high |
- C ebx (h.low) |
- C ecx counter, -size+2 to 0 or 1 |
- C edx (h.high) |
- C esi &src[size] |
- C edi &dst[size] |
- C ebp |
- C |
- C %mm0 (high products) |
- C %mm1 (low products) |
- C %mm2 (adjust for m using x signs) |
- C %mm3 (adjust for x using m signs) |
- C %mm4 |
- C %mm5 |
- C %mm6 h.low, then carry |
- C %mm7 m replicated 4 times |
- |
- movd %mm6, %ebx C h.low |
- psrlq $32, %mm1 C l.high |
- |
- movd %mm0, %edx C h.high |
- movq %mm0, %mm6 C new c |
- |
- adcl %eax, %ebx |
- incl %ecx |
- |
- movd %mm1, %eax C l.high |
- movq %mm7, %mm0 |
- |
- adcl %eax, %edx |
- movl %ebx, -16(%edi,%ecx,4) |
- |
- movl %edx, -12(%edi,%ecx,4) |
- psrlq $32, %mm6 C c |
- |
-L(small_entry): |
- pmulhw -8(%esi,%ecx,4), %mm0 C h = (x*m).high |
- movq %mm7, %mm1 |
- |
- pmullw -8(%esi,%ecx,4), %mm1 C l = (x*m).low |
- movq %mm7, %mm3 |
- |
- movq -8(%esi,%ecx,4), %mm2 C x |
- psraw $15, %mm3 C m signs |
- |
- pand -8(%esi,%ecx,4), %mm3 C x selected by m signs |
- psraw $15, %mm2 C x signs |
- |
- paddw %mm3, %mm0 C add x to h if m neg |
- pand %mm7, %mm2 C m selected by x signs |
- |
- paddw %mm2, %mm0 C add m to h if x neg |
- incl %ecx |
- |
- movd %mm1, %eax C l.low |
- punpcklwd %mm0, %mm6 C c + h.low << 16 |
- |
- psrlq $16, %mm0 C h.high |
- js L(small_top) |
- |
- |
- |
- |
- movd %mm6, %ebx C h.low |
- psrlq $32, %mm1 C l.high |
- |
- adcl %eax, %ebx |
- popl %ebp FRAME_popl() |
- |
- movd %mm0, %edx C h.high |
- psrlq $32, %mm0 C l.high |
- |
- movd %mm1, %eax C l.high |
- |
- adcl %eax, %edx |
- movl %ebx, -12(%edi,%ecx,4) |
- |
- movd %mm0, %eax C c |
- |
- adcl $0, %eax |
- movl %edx, -8(%edi,%ecx,4) |
- |
- orl %ecx, %ecx |
- jnz L(small_done) C final %ecx==1 means even, ==0 odd |
- |
- |
- C Size odd, one extra limb to process. |
- C Plain integer code is used here, since it's smaller and is about |
- C the same speed as another mmx block would be. |
- |
- movl %eax, %ecx |
- movl PARAM_MULTIPLIER, %eax |
- |
- mull -4(%esi) |
- |
- addl %ecx, %eax |
- |
- adcl $0, %edx |
- movl %eax, -4(%edi) |
- |
- movl %edx, %eax |
-L(small_done): |
- popl %ebx |
- |
- popl %edi |
- popl %esi |
- |
- emms |
- |
- ret |
- |
-EPILOGUE() |