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-rw-r--r--QW/client/d_draw16.s974
1 files changed, 974 insertions, 0 deletions
diff --git a/QW/client/d_draw16.s b/QW/client/d_draw16.s
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+/*
+Copyright (C) 1996-1997 Id Software, Inc.
+
+This program is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License
+as published by the Free Software Foundation; either version 2
+of the License, or (at your option) any later version.
+
+This program 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 General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+*/
+//
+// d_draw16.s
+// x86 assembly-language horizontal 8-bpp span-drawing code, with 16-pixel
+// subdivision.
+//
+
+#include "asm_i386.h"
+#include "quakeasm.h"
+#include "asm_draw.h"
+#include "d_ifacea.h"
+
+#if id386
+
+//----------------------------------------------------------------------
+// 8-bpp horizontal span drawing code for polygons, with no transparency and
+// 16-pixel subdivision.
+//
+// Assumes there is at least one span in pspans, and that every span
+// contains at least one pixel
+//----------------------------------------------------------------------
+
+ .data
+
+ .text
+
+// out-of-line, rarely-needed clamping code
+
+LClampHigh0:
+ movl C(bbextents),%esi
+ jmp LClampReentry0
+LClampHighOrLow0:
+ jg LClampHigh0
+ xorl %esi,%esi
+ jmp LClampReentry0
+
+LClampHigh1:
+ movl C(bbextentt),%edx
+ jmp LClampReentry1
+LClampHighOrLow1:
+ jg LClampHigh1
+ xorl %edx,%edx
+ jmp LClampReentry1
+
+LClampLow2:
+ movl $4096,%ebp
+ jmp LClampReentry2
+LClampHigh2:
+ movl C(bbextents),%ebp
+ jmp LClampReentry2
+
+LClampLow3:
+ movl $4096,%ecx
+ jmp LClampReentry3
+LClampHigh3:
+ movl C(bbextentt),%ecx
+ jmp LClampReentry3
+
+LClampLow4:
+ movl $4096,%eax
+ jmp LClampReentry4
+LClampHigh4:
+ movl C(bbextents),%eax
+ jmp LClampReentry4
+
+LClampLow5:
+ movl $4096,%ebx
+ jmp LClampReentry5
+LClampHigh5:
+ movl C(bbextentt),%ebx
+ jmp LClampReentry5
+
+
+#define pspans 4+16
+
+ .align 4
+.globl C(D_DrawSpans16)
+C(D_DrawSpans16):
+ pushl %ebp // preserve caller's stack frame
+ pushl %edi
+ pushl %esi // preserve register variables
+ pushl %ebx
+
+//
+// set up scaled-by-16 steps, for 16-long segments; also set up cacheblock
+// and span list pointers
+//
+// TODO: any overlap from rearranging?
+ flds C(d_sdivzstepu)
+ fmuls fp_16
+ movl C(cacheblock),%edx
+ flds C(d_tdivzstepu)
+ fmuls fp_16
+ movl pspans(%esp),%ebx // point to the first span descriptor
+ flds C(d_zistepu)
+ fmuls fp_16
+ movl %edx,pbase // pbase = cacheblock
+ fstps zi16stepu
+ fstps tdivz16stepu
+ fstps sdivz16stepu
+
+LSpanLoop:
+//
+// set up the initial s/z, t/z, and 1/z on the FP stack, and generate the
+// initial s and t values
+//
+// FIXME: pipeline FILD?
+ fildl espan_t_v(%ebx)
+ fildl espan_t_u(%ebx)
+
+ fld %st(1) // dv | du | dv
+ fmuls C(d_sdivzstepv) // dv*d_sdivzstepv | du | dv
+ fld %st(1) // du | dv*d_sdivzstepv | du | dv
+ fmuls C(d_sdivzstepu) // du*d_sdivzstepu | dv*d_sdivzstepv | du | dv
+ fld %st(2) // du | du*d_sdivzstepu | dv*d_sdivzstepv | du | dv
+ fmuls C(d_tdivzstepu) // du*d_tdivzstepu | du*d_sdivzstepu |
+ // dv*d_sdivzstepv | du | dv
+ fxch %st(1) // du*d_sdivzstepu | du*d_tdivzstepu |
+ // dv*d_sdivzstepv | du | dv
+ faddp %st(0),%st(2) // du*d_tdivzstepu |
+ // du*d_sdivzstepu + dv*d_sdivzstepv | du | dv
+ fxch %st(1) // du*d_sdivzstepu + dv*d_sdivzstepv |
+ // du*d_tdivzstepu | du | dv
+ fld %st(3) // dv | du*d_sdivzstepu + dv*d_sdivzstepv |
+ // du*d_tdivzstepu | du | dv
+ fmuls C(d_tdivzstepv) // dv*d_tdivzstepv |
+ // du*d_sdivzstepu + dv*d_sdivzstepv |
+ // du*d_tdivzstepu | du | dv
+ fxch %st(1) // du*d_sdivzstepu + dv*d_sdivzstepv |
+ // dv*d_tdivzstepv | du*d_tdivzstepu | du | dv
+ fadds C(d_sdivzorigin) // sdivz = d_sdivzorigin + dv*d_sdivzstepv +
+ // du*d_sdivzstepu; stays in %st(2) at end
+ fxch %st(4) // dv | dv*d_tdivzstepv | du*d_tdivzstepu | du |
+ // s/z
+ fmuls C(d_zistepv) // dv*d_zistepv | dv*d_tdivzstepv |
+ // du*d_tdivzstepu | du | s/z
+ fxch %st(1) // dv*d_tdivzstepv | dv*d_zistepv |
+ // du*d_tdivzstepu | du | s/z
+ faddp %st(0),%st(2) // dv*d_zistepv |
+ // dv*d_tdivzstepv + du*d_tdivzstepu | du | s/z
+ fxch %st(2) // du | dv*d_tdivzstepv + du*d_tdivzstepu |
+ // dv*d_zistepv | s/z
+ fmuls C(d_zistepu) // du*d_zistepu |
+ // dv*d_tdivzstepv + du*d_tdivzstepu |
+ // dv*d_zistepv | s/z
+ fxch %st(1) // dv*d_tdivzstepv + du*d_tdivzstepu |
+ // du*d_zistepu | dv*d_zistepv | s/z
+ fadds C(d_tdivzorigin) // tdivz = d_tdivzorigin + dv*d_tdivzstepv +
+ // du*d_tdivzstepu; stays in %st(1) at end
+ fxch %st(2) // dv*d_zistepv | du*d_zistepu | t/z | s/z
+ faddp %st(0),%st(1) // dv*d_zistepv + du*d_zistepu | t/z | s/z
+
+ flds fp_64k // fp_64k | dv*d_zistepv + du*d_zistepu | t/z | s/z
+ fxch %st(1) // dv*d_zistepv + du*d_zistepu | fp_64k | t/z | s/z
+ fadds C(d_ziorigin) // zi = d_ziorigin + dv*d_zistepv +
+ // du*d_zistepu; stays in %st(0) at end
+ // 1/z | fp_64k | t/z | s/z
+//
+// calculate and clamp s & t
+//
+ fdivr %st(0),%st(1) // 1/z | z*64k | t/z | s/z
+
+//
+// point %edi to the first pixel in the span
+//
+ movl C(d_viewbuffer),%ecx
+ movl espan_t_v(%ebx),%eax
+ movl %ebx,pspantemp // preserve spans pointer
+
+ movl C(tadjust),%edx
+ movl C(sadjust),%esi
+ movl C(d_scantable)(,%eax,4),%edi // v * screenwidth
+ addl %ecx,%edi
+ movl espan_t_u(%ebx),%ecx
+ addl %ecx,%edi // pdest = &pdestspan[scans->u];
+ movl espan_t_count(%ebx),%ecx
+
+//
+// now start the FDIV for the end of the span
+//
+ cmpl $16,%ecx
+ ja LSetupNotLast1
+
+ decl %ecx
+ jz LCleanup1 // if only one pixel, no need to start an FDIV
+ movl %ecx,spancountminus1
+
+// finish up the s and t calcs
+ fxch %st(1) // z*64k | 1/z | t/z | s/z
+
+ fld %st(0) // z*64k | z*64k | 1/z | t/z | s/z
+ fmul %st(4),%st(0) // s | z*64k | 1/z | t/z | s/z
+ fxch %st(1) // z*64k | s | 1/z | t/z | s/z
+ fmul %st(3),%st(0) // t | s | 1/z | t/z | s/z
+ fxch %st(1) // s | t | 1/z | t/z | s/z
+ fistpl s // 1/z | t | t/z | s/z
+ fistpl t // 1/z | t/z | s/z
+
+ fildl spancountminus1
+
+ flds C(d_tdivzstepu) // C(d_tdivzstepu) | spancountminus1
+ flds C(d_zistepu) // C(d_zistepu) | C(d_tdivzstepu) | spancountminus1
+ fmul %st(2),%st(0) // C(d_zistepu)*scm1 | C(d_tdivzstepu) | scm1
+ fxch %st(1) // C(d_tdivzstepu) | C(d_zistepu)*scm1 | scm1
+ fmul %st(2),%st(0) // C(d_tdivzstepu)*scm1 | C(d_zistepu)*scm1 | scm1
+ fxch %st(2) // scm1 | C(d_zistepu)*scm1 | C(d_tdivzstepu)*scm1
+ fmuls C(d_sdivzstepu) // C(d_sdivzstepu)*scm1 | C(d_zistepu)*scm1 |
+ // C(d_tdivzstepu)*scm1
+ fxch %st(1) // C(d_zistepu)*scm1 | C(d_sdivzstepu)*scm1 |
+ // C(d_tdivzstepu)*scm1
+ faddp %st(0),%st(3) // C(d_sdivzstepu)*scm1 | C(d_tdivzstepu)*scm1
+ fxch %st(1) // C(d_tdivzstepu)*scm1 | C(d_sdivzstepu)*scm1
+ faddp %st(0),%st(3) // C(d_sdivzstepu)*scm1
+ faddp %st(0),%st(3)
+
+ flds fp_64k
+ fdiv %st(1),%st(0) // this is what we've gone to all this trouble to
+ // overlap
+ jmp LFDIVInFlight1
+
+LCleanup1:
+// finish up the s and t calcs
+ fxch %st(1) // z*64k | 1/z | t/z | s/z
+
+ fld %st(0) // z*64k | z*64k | 1/z | t/z | s/z
+ fmul %st(4),%st(0) // s | z*64k | 1/z | t/z | s/z
+ fxch %st(1) // z*64k | s | 1/z | t/z | s/z
+ fmul %st(3),%st(0) // t | s | 1/z | t/z | s/z
+ fxch %st(1) // s | t | 1/z | t/z | s/z
+ fistpl s // 1/z | t | t/z | s/z
+ fistpl t // 1/z | t/z | s/z
+ jmp LFDIVInFlight1
+
+ .align 4
+LSetupNotLast1:
+// finish up the s and t calcs
+ fxch %st(1) // z*64k | 1/z | t/z | s/z
+
+ fld %st(0) // z*64k | z*64k | 1/z | t/z | s/z
+ fmul %st(4),%st(0) // s | z*64k | 1/z | t/z | s/z
+ fxch %st(1) // z*64k | s | 1/z | t/z | s/z
+ fmul %st(3),%st(0) // t | s | 1/z | t/z | s/z
+ fxch %st(1) // s | t | 1/z | t/z | s/z
+ fistpl s // 1/z | t | t/z | s/z
+ fistpl t // 1/z | t/z | s/z
+
+ fadds zi16stepu
+ fxch %st(2)
+ fadds sdivz16stepu
+ fxch %st(2)
+ flds tdivz16stepu
+ faddp %st(0),%st(2)
+ flds fp_64k
+ fdiv %st(1),%st(0) // z = 1/1/z
+ // this is what we've gone to all this trouble to
+ // overlap
+LFDIVInFlight1:
+
+ addl s,%esi
+ addl t,%edx
+ movl C(bbextents),%ebx
+ movl C(bbextentt),%ebp
+ cmpl %ebx,%esi
+ ja LClampHighOrLow0
+LClampReentry0:
+ movl %esi,s
+ movl pbase,%ebx
+ shll $16,%esi
+ cmpl %ebp,%edx
+ movl %esi,sfracf
+ ja LClampHighOrLow1
+LClampReentry1:
+ movl %edx,t
+ movl s,%esi // sfrac = scans->sfrac;
+ shll $16,%edx
+ movl t,%eax // tfrac = scans->tfrac;
+ sarl $16,%esi
+ movl %edx,tfracf
+
+//
+// calculate the texture starting address
+//
+ sarl $16,%eax
+ movl C(cachewidth),%edx
+ imull %edx,%eax // (tfrac >> 16) * cachewidth
+ addl %ebx,%esi
+ addl %eax,%esi // psource = pbase + (sfrac >> 16) +
+ // ((tfrac >> 16) * cachewidth);
+//
+// determine whether last span or not
+//
+ cmpl $16,%ecx
+ jna LLastSegment
+
+//
+// not the last segment; do full 16-wide segment
+//
+LNotLastSegment:
+
+//
+// advance s/z, t/z, and 1/z, and calculate s & t at end of span and steps to
+// get there
+//
+
+// pick up after the FDIV that was left in flight previously
+
+ fld %st(0) // duplicate it
+ fmul %st(4),%st(0) // s = s/z * z
+ fxch %st(1)
+ fmul %st(3),%st(0) // t = t/z * z
+ fxch %st(1)
+ fistpl snext
+ fistpl tnext
+ movl snext,%eax
+ movl tnext,%edx
+
+ movb (%esi),%bl // get first source texel
+ subl $16,%ecx // count off this segments' pixels
+ movl C(sadjust),%ebp
+ movl %ecx,counttemp // remember count of remaining pixels
+
+ movl C(tadjust),%ecx
+ movb %bl,(%edi) // store first dest pixel
+
+ addl %eax,%ebp
+ addl %edx,%ecx
+
+ movl C(bbextents),%eax
+ movl C(bbextentt),%edx
+
+ cmpl $4096,%ebp
+ jl LClampLow2
+ cmpl %eax,%ebp
+ ja LClampHigh2
+LClampReentry2:
+
+ cmpl $4096,%ecx
+ jl LClampLow3
+ cmpl %edx,%ecx
+ ja LClampHigh3
+LClampReentry3:
+
+ movl %ebp,snext
+ movl %ecx,tnext
+
+ subl s,%ebp
+ subl t,%ecx
+
+//
+// set up advancetable
+//
+ movl %ecx,%eax
+ movl %ebp,%edx
+ sarl $20,%eax // tstep >>= 16;
+ jz LZero
+ sarl $20,%edx // sstep >>= 16;
+ movl C(cachewidth),%ebx
+ imull %ebx,%eax
+ jmp LSetUp1
+
+LZero:
+ sarl $20,%edx // sstep >>= 16;
+ movl C(cachewidth),%ebx
+
+LSetUp1:
+
+ addl %edx,%eax // add in sstep
+ // (tstep >> 16) * cachewidth + (sstep >> 16);
+ movl tfracf,%edx
+ movl %eax,advancetable+4 // advance base in t
+ addl %ebx,%eax // ((tstep >> 16) + 1) * cachewidth +
+ // (sstep >> 16);
+ shll $12,%ebp // left-justify sstep fractional part
+ movl sfracf,%ebx
+ shll $12,%ecx // left-justify tstep fractional part
+ movl %eax,advancetable // advance extra in t
+
+ movl %ecx,tstep
+ addl %ecx,%edx // advance tfrac fractional part by tstep frac
+
+ sbbl %ecx,%ecx // turn tstep carry into -1 (0 if none)
+ addl %ebp,%ebx // advance sfrac fractional part by sstep frac
+ adcl advancetable+4(,%ecx,4),%esi // point to next source texel
+
+ addl tstep,%edx
+ sbbl %ecx,%ecx
+ movb (%esi),%al
+ addl %ebp,%ebx
+ movb %al,1(%edi)
+ adcl advancetable+4(,%ecx,4),%esi
+
+ addl tstep,%edx
+ sbbl %ecx,%ecx
+ addl %ebp,%ebx
+ movb (%esi),%al
+ adcl advancetable+4(,%ecx,4),%esi
+
+ addl tstep,%edx
+ sbbl %ecx,%ecx
+ movb %al,2(%edi)
+ addl %ebp,%ebx
+ movb (%esi),%al
+ adcl advancetable+4(,%ecx,4),%esi
+
+ addl tstep,%edx
+ sbbl %ecx,%ecx
+ movb %al,3(%edi)
+ addl %ebp,%ebx
+ movb (%esi),%al
+ adcl advancetable+4(,%ecx,4),%esi
+
+ addl tstep,%edx
+ sbbl %ecx,%ecx
+ movb %al,4(%edi)
+ addl %ebp,%ebx
+ movb (%esi),%al
+ adcl advancetable+4(,%ecx,4),%esi
+
+ addl tstep,%edx
+ sbbl %ecx,%ecx
+ movb %al,5(%edi)
+ addl %ebp,%ebx
+ movb (%esi),%al
+ adcl advancetable+4(,%ecx,4),%esi
+
+ addl tstep,%edx
+ sbbl %ecx,%ecx
+ movb %al,6(%edi)
+ addl %ebp,%ebx
+ movb (%esi),%al
+ adcl advancetable+4(,%ecx,4),%esi
+
+ addl tstep,%edx
+ sbbl %ecx,%ecx
+ movb %al,7(%edi)
+ addl %ebp,%ebx
+ movb (%esi),%al
+ adcl advancetable+4(,%ecx,4),%esi
+
+
+//
+// start FDIV for end of next segment in flight, so it can overlap
+//
+ movl counttemp,%ecx
+ cmpl $16,%ecx // more than one segment after this?
+ ja LSetupNotLast2 // yes
+
+ decl %ecx
+ jz LFDIVInFlight2 // if only one pixel, no need to start an FDIV
+ movl %ecx,spancountminus1
+ fildl spancountminus1
+
+ flds C(d_zistepu) // C(d_zistepu) | spancountminus1
+ fmul %st(1),%st(0) // C(d_zistepu)*scm1 | scm1
+ flds C(d_tdivzstepu) // C(d_tdivzstepu) | C(d_zistepu)*scm1 | scm1
+ fmul %st(2),%st(0) // C(d_tdivzstepu)*scm1 | C(d_zistepu)*scm1 | scm1
+ fxch %st(1) // C(d_zistepu)*scm1 | C(d_tdivzstepu)*scm1 | scm1
+ faddp %st(0),%st(3) // C(d_tdivzstepu)*scm1 | scm1
+ fxch %st(1) // scm1 | C(d_tdivzstepu)*scm1
+ fmuls C(d_sdivzstepu) // C(d_sdivzstepu)*scm1 | C(d_tdivzstepu)*scm1
+ fxch %st(1) // C(d_tdivzstepu)*scm1 | C(d_sdivzstepu)*scm1
+ faddp %st(0),%st(3) // C(d_sdivzstepu)*scm1
+ flds fp_64k // 64k | C(d_sdivzstepu)*scm1
+ fxch %st(1) // C(d_sdivzstepu)*scm1 | 64k
+ faddp %st(0),%st(4) // 64k
+
+ fdiv %st(1),%st(0) // this is what we've gone to all this trouble to
+ // overlap
+ jmp LFDIVInFlight2
+
+ .align 4
+LSetupNotLast2:
+ fadds zi16stepu
+ fxch %st(2)
+ fadds sdivz16stepu
+ fxch %st(2)
+ flds tdivz16stepu
+ faddp %st(0),%st(2)
+ flds fp_64k
+ fdiv %st(1),%st(0) // z = 1/1/z
+ // this is what we've gone to all this trouble to
+ // overlap
+LFDIVInFlight2:
+ movl %ecx,counttemp
+
+ addl tstep,%edx
+ sbbl %ecx,%ecx
+ movb %al,8(%edi)
+ addl %ebp,%ebx
+ movb (%esi),%al
+ adcl advancetable+4(,%ecx,4),%esi
+
+ addl tstep,%edx
+ sbbl %ecx,%ecx
+ movb %al,9(%edi)
+ addl %ebp,%ebx
+ movb (%esi),%al
+ adcl advancetable+4(,%ecx,4),%esi
+
+ addl tstep,%edx
+ sbbl %ecx,%ecx
+ movb %al,10(%edi)
+ addl %ebp,%ebx
+ movb (%esi),%al
+ adcl advancetable+4(,%ecx,4),%esi
+
+ addl tstep,%edx
+ sbbl %ecx,%ecx
+ movb %al,11(%edi)
+ addl %ebp,%ebx
+ movb (%esi),%al
+ adcl advancetable+4(,%ecx,4),%esi
+
+ addl tstep,%edx
+ sbbl %ecx,%ecx
+ movb %al,12(%edi)
+ addl %ebp,%ebx
+ movb (%esi),%al
+ adcl advancetable+4(,%ecx,4),%esi
+
+ addl tstep,%edx
+ sbbl %ecx,%ecx
+ movb %al,13(%edi)
+ addl %ebp,%ebx
+ movb (%esi),%al
+ adcl advancetable+4(,%ecx,4),%esi
+
+ addl tstep,%edx
+ sbbl %ecx,%ecx
+ movb %al,14(%edi)
+ addl %ebp,%ebx
+ movb (%esi),%al
+ adcl advancetable+4(,%ecx,4),%esi
+
+ addl $16,%edi
+ movl %edx,tfracf
+ movl snext,%edx
+ movl %ebx,sfracf
+ movl tnext,%ebx
+ movl %edx,s
+ movl %ebx,t
+
+ movl counttemp,%ecx // retrieve count
+
+//
+// determine whether last span or not
+//
+ cmpl $16,%ecx // are there multiple segments remaining?
+ movb %al,-1(%edi)
+ ja LNotLastSegment // yes
+
+//
+// last segment of scan
+//
+LLastSegment:
+
+//
+// advance s/z, t/z, and 1/z, and calculate s & t at end of span and steps to
+// get there. The number of pixels left is variable, and we want to land on the
+// last pixel, not step one past it, so we can't run into arithmetic problems
+//
+ testl %ecx,%ecx
+ jz LNoSteps // just draw the last pixel and we're done
+
+// pick up after the FDIV that was left in flight previously
+
+
+ fld %st(0) // duplicate it
+ fmul %st(4),%st(0) // s = s/z * z
+ fxch %st(1)
+ fmul %st(3),%st(0) // t = t/z * z
+ fxch %st(1)
+ fistpl snext
+ fistpl tnext
+
+ movb (%esi),%al // load first texel in segment
+ movl C(tadjust),%ebx
+ movb %al,(%edi) // store first pixel in segment
+ movl C(sadjust),%eax
+
+ addl snext,%eax
+ addl tnext,%ebx
+
+ movl C(bbextents),%ebp
+ movl C(bbextentt),%edx
+
+ cmpl $4096,%eax
+ jl LClampLow4
+ cmpl %ebp,%eax
+ ja LClampHigh4
+LClampReentry4:
+ movl %eax,snext
+
+ cmpl $4096,%ebx
+ jl LClampLow5
+ cmpl %edx,%ebx
+ ja LClampHigh5
+LClampReentry5:
+
+ cmpl $1,%ecx // don't bother
+ je LOnlyOneStep // if two pixels in segment, there's only one step,
+ // of the segment length
+ subl s,%eax
+ subl t,%ebx
+
+ addl %eax,%eax // convert to 15.17 format so multiply by 1.31
+ addl %ebx,%ebx // reciprocal yields 16.48
+
+ imull reciprocal_table_16-8(,%ecx,4) // sstep = (snext - s) /
+ // (spancount-1)
+ movl %edx,%ebp
+
+ movl %ebx,%eax
+ imull reciprocal_table_16-8(,%ecx,4) // tstep = (tnext - t) /
+ // (spancount-1)
+LSetEntryvec:
+//
+// set up advancetable
+//
+ movl entryvec_table_16(,%ecx,4),%ebx
+ movl %edx,%eax
+ movl %ebx,jumptemp // entry point into code for RET later
+ movl %ebp,%ecx
+ sarl $16,%edx // tstep >>= 16;
+ movl C(cachewidth),%ebx
+ sarl $16,%ecx // sstep >>= 16;
+ imull %ebx,%edx
+
+ addl %ecx,%edx // add in sstep
+ // (tstep >> 16) * cachewidth + (sstep >> 16);
+ movl tfracf,%ecx
+ movl %edx,advancetable+4 // advance base in t
+ addl %ebx,%edx // ((tstep >> 16) + 1) * cachewidth +
+ // (sstep >> 16);
+ shll $16,%ebp // left-justify sstep fractional part
+ movl sfracf,%ebx
+ shll $16,%eax // left-justify tstep fractional part
+ movl %edx,advancetable // advance extra in t
+
+ movl %eax,tstep
+ movl %ecx,%edx
+ addl %eax,%edx
+ sbbl %ecx,%ecx
+ addl %ebp,%ebx
+ adcl advancetable+4(,%ecx,4),%esi
+
+ jmp *jumptemp // jump to the number-of-pixels handler
+
+//----------------------------------------
+
+LNoSteps:
+ movb (%esi),%al // load first texel in segment
+ subl $15,%edi // adjust for hardwired offset
+ jmp LEndSpan
+
+
+LOnlyOneStep:
+ subl s,%eax
+ subl t,%ebx
+ movl %eax,%ebp
+ movl %ebx,%edx
+ jmp LSetEntryvec
+
+//----------------------------------------
+
+.globl Entry2_16, Entry3_16, Entry4_16, Entry5_16
+.globl Entry6_16, Entry7_16, Entry8_16, Entry9_16
+.globl Entry10_16, Entry11_16, Entry12_16, Entry13_16
+.globl Entry14_16, Entry15_16, Entry16_16
+
+Entry2_16:
+ subl $14,%edi // adjust for hardwired offsets
+ movb (%esi),%al
+ jmp LEntry2_16
+
+//----------------------------------------
+
+Entry3_16:
+ subl $13,%edi // adjust for hardwired offsets
+ addl %eax,%edx
+ movb (%esi),%al
+ sbbl %ecx,%ecx
+ addl %ebp,%ebx
+ adcl advancetable+4(,%ecx,4),%esi
+ jmp LEntry3_16
+
+//----------------------------------------
+
+Entry4_16:
+ subl $12,%edi // adjust for hardwired offsets
+ addl %eax,%edx
+ movb (%esi),%al
+ sbbl %ecx,%ecx
+ addl %ebp,%ebx
+ adcl advancetable+4(,%ecx,4),%esi
+ addl tstep,%edx
+ jmp LEntry4_16
+
+//----------------------------------------
+
+Entry5_16:
+ subl $11,%edi // adjust for hardwired offsets
+ addl %eax,%edx
+ movb (%esi),%al
+ sbbl %ecx,%ecx
+ addl %ebp,%ebx
+ adcl advancetable+4(,%ecx,4),%esi
+ addl tstep,%edx
+ jmp LEntry5_16
+
+//----------------------------------------
+
+Entry6_16:
+ subl $10,%edi // adjust for hardwired offsets
+ addl %eax,%edx
+ movb (%esi),%al
+ sbbl %ecx,%ecx
+ addl %ebp,%ebx
+ adcl advancetable+4(,%ecx,4),%esi
+ addl tstep,%edx
+ jmp LEntry6_16
+
+//----------------------------------------
+
+Entry7_16:
+ subl $9,%edi // adjust for hardwired offsets
+ addl %eax,%edx
+ movb (%esi),%al
+ sbbl %ecx,%ecx
+ addl %ebp,%ebx
+ adcl advancetable+4(,%ecx,4),%esi
+ addl tstep,%edx
+ jmp LEntry7_16
+
+//----------------------------------------
+
+Entry8_16:
+ subl $8,%edi // adjust for hardwired offsets
+ addl %eax,%edx
+ movb (%esi),%al
+ sbbl %ecx,%ecx
+ addl %ebp,%ebx
+ adcl advancetable+4(,%ecx,4),%esi
+ addl tstep,%edx
+ jmp LEntry8_16
+
+//----------------------------------------
+
+Entry9_16:
+ subl $7,%edi // adjust for hardwired offsets
+ addl %eax,%edx
+ movb (%esi),%al
+ sbbl %ecx,%ecx
+ addl %ebp,%ebx
+ adcl advancetable+4(,%ecx,4),%esi
+ addl tstep,%edx
+ jmp LEntry9_16
+
+//----------------------------------------
+
+Entry10_16:
+ subl $6,%edi // adjust for hardwired offsets
+ addl %eax,%edx
+ movb (%esi),%al
+ sbbl %ecx,%ecx
+ addl %ebp,%ebx
+ adcl advancetable+4(,%ecx,4),%esi
+ addl tstep,%edx
+ jmp LEntry10_16
+
+//----------------------------------------
+
+Entry11_16:
+ subl $5,%edi // adjust for hardwired offsets
+ addl %eax,%edx
+ movb (%esi),%al
+ sbbl %ecx,%ecx
+ addl %ebp,%ebx
+ adcl advancetable+4(,%ecx,4),%esi
+ addl tstep,%edx
+ jmp LEntry11_16
+
+//----------------------------------------
+
+Entry12_16:
+ subl $4,%edi // adjust for hardwired offsets
+ addl %eax,%edx
+ movb (%esi),%al
+ sbbl %ecx,%ecx
+ addl %ebp,%ebx
+ adcl advancetable+4(,%ecx,4),%esi
+ addl tstep,%edx
+ jmp LEntry12_16
+
+//----------------------------------------
+
+Entry13_16:
+ subl $3,%edi // adjust for hardwired offsets
+ addl %eax,%edx
+ movb (%esi),%al
+ sbbl %ecx,%ecx
+ addl %ebp,%ebx
+ adcl advancetable+4(,%ecx,4),%esi
+ addl tstep,%edx
+ jmp LEntry13_16
+
+//----------------------------------------
+
+Entry14_16:
+ subl $2,%edi // adjust for hardwired offsets
+ addl %eax,%edx
+ movb (%esi),%al
+ sbbl %ecx,%ecx
+ addl %ebp,%ebx
+ adcl advancetable+4(,%ecx,4),%esi
+ addl tstep,%edx
+ jmp LEntry14_16
+
+//----------------------------------------
+
+Entry15_16:
+ decl %edi // adjust for hardwired offsets
+ addl %eax,%edx
+ movb (%esi),%al
+ sbbl %ecx,%ecx
+ addl %ebp,%ebx
+ adcl advancetable+4(,%ecx,4),%esi
+ addl tstep,%edx
+ jmp LEntry15_16
+
+//----------------------------------------
+
+Entry16_16:
+ addl %eax,%edx
+ movb (%esi),%al
+ sbbl %ecx,%ecx
+ addl %ebp,%ebx
+ adcl advancetable+4(,%ecx,4),%esi
+
+ addl tstep,%edx
+ sbbl %ecx,%ecx
+ movb %al,1(%edi)
+ addl %ebp,%ebx
+ movb (%esi),%al
+ adcl advancetable+4(,%ecx,4),%esi
+ addl tstep,%edx
+LEntry15_16:
+ sbbl %ecx,%ecx
+ movb %al,2(%edi)
+ addl %ebp,%ebx
+ movb (%esi),%al
+ adcl advancetable+4(,%ecx,4),%esi
+ addl tstep,%edx
+LEntry14_16:
+ sbbl %ecx,%ecx
+ movb %al,3(%edi)
+ addl %ebp,%ebx
+ movb (%esi),%al
+ adcl advancetable+4(,%ecx,4),%esi
+ addl tstep,%edx
+LEntry13_16:
+ sbbl %ecx,%ecx
+ movb %al,4(%edi)
+ addl %ebp,%ebx
+ movb (%esi),%al
+ adcl advancetable+4(,%ecx,4),%esi
+ addl tstep,%edx
+LEntry12_16:
+ sbbl %ecx,%ecx
+ movb %al,5(%edi)
+ addl %ebp,%ebx
+ movb (%esi),%al
+ adcl advancetable+4(,%ecx,4),%esi
+ addl tstep,%edx
+LEntry11_16:
+ sbbl %ecx,%ecx
+ movb %al,6(%edi)
+ addl %ebp,%ebx
+ movb (%esi),%al
+ adcl advancetable+4(,%ecx,4),%esi
+ addl tstep,%edx
+LEntry10_16:
+ sbbl %ecx,%ecx
+ movb %al,7(%edi)
+ addl %ebp,%ebx
+ movb (%esi),%al
+ adcl advancetable+4(,%ecx,4),%esi
+ addl tstep,%edx
+LEntry9_16:
+ sbbl %ecx,%ecx
+ movb %al,8(%edi)
+ addl %ebp,%ebx
+ movb (%esi),%al
+ adcl advancetable+4(,%ecx,4),%esi
+ addl tstep,%edx
+LEntry8_16:
+ sbbl %ecx,%ecx
+ movb %al,9(%edi)
+ addl %ebp,%ebx
+ movb (%esi),%al
+ adcl advancetable+4(,%ecx,4),%esi
+ addl tstep,%edx
+LEntry7_16:
+ sbbl %ecx,%ecx
+ movb %al,10(%edi)
+ addl %ebp,%ebx
+ movb (%esi),%al
+ adcl advancetable+4(,%ecx,4),%esi
+ addl tstep,%edx
+LEntry6_16:
+ sbbl %ecx,%ecx
+ movb %al,11(%edi)
+ addl %ebp,%ebx
+ movb (%esi),%al
+ adcl advancetable+4(,%ecx,4),%esi
+ addl tstep,%edx
+LEntry5_16:
+ sbbl %ecx,%ecx
+ movb %al,12(%edi)
+ addl %ebp,%ebx
+ movb (%esi),%al
+ adcl advancetable+4(,%ecx,4),%esi
+ addl tstep,%edx
+LEntry4_16:
+ sbbl %ecx,%ecx
+ movb %al,13(%edi)
+ addl %ebp,%ebx
+ movb (%esi),%al
+ adcl advancetable+4(,%ecx,4),%esi
+LEntry3_16:
+ movb %al,14(%edi)
+ movb (%esi),%al
+LEntry2_16:
+
+LEndSpan:
+
+//
+// clear s/z, t/z, 1/z from FP stack
+//
+ fstp %st(0)
+ fstp %st(0)
+ fstp %st(0)
+
+ movl pspantemp,%ebx // restore spans pointer
+ movl espan_t_pnext(%ebx),%ebx // point to next span
+ testl %ebx,%ebx // any more spans?
+ movb %al,15(%edi)
+ jnz LSpanLoop // more spans
+
+ popl %ebx // restore register variables
+ popl %esi
+ popl %edi
+ popl %ebp // restore the caller's stack frame
+ ret
+
+#endif // id386
generated by cgit v1.2.3 (git 2.39.1) at 2026-10-05 23:44:55 +0000