KonstantinSeurer
/
mesa
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

i965: Add support for dFdx()/dFdy() to the FS backend. 

Fixes:
glsl-fwidth
glsl-derivs-swizzle
This commit is contained in:
Eric Anholt 2010-09-27 18:31:53 -07:00
parent 3610e0c1a0
commit 94d44c33c0
1 changed files with 71 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

71
src/mesa/drivers/dri/i965/brw_fs.cpp
View File

@ -428,6 +428,8 @@ public:
void generate_tex(fs_inst *inst, struct brw_reg dst, struct brw_reg src);
void generate_math(fs_inst *inst, struct brw_reg dst, struct brw_reg *src);
void generate_discard(fs_inst *inst);
void generate_ddx(fs_inst *inst, struct brw_reg dst, struct brw_reg src);
void generate_ddy(fs_inst *inst, struct brw_reg dst, struct brw_reg src);
void emit_dummy_fs();
void emit_interpolation();
@ -1496,6 +1498,69 @@ fs_visitor::generate_tex(fs_inst *inst, struct brw_reg dst, struct brw_reg src)
BRW_SAMPLER_SIMD_MODE_SIMD8);
}
/* For OPCODE_DDX and OPCODE_DDY, per channel of output we've got input
* looking like:
*
* arg0: ss0.tl ss0.tr ss0.bl ss0.br ss1.tl ss1.tr ss1.bl ss1.br
*
* and we're trying to produce:
*
* DDX DDY
* dst: (ss0.tr - ss0.tl) (ss0.tl - ss0.bl)
* (ss0.tr - ss0.tl) (ss0.tr - ss0.br)
* (ss0.br - ss0.bl) (ss0.tl - ss0.bl)
* (ss0.br - ss0.bl) (ss0.tr - ss0.br)
* (ss1.tr - ss1.tl) (ss1.tl - ss1.bl)
* (ss1.tr - ss1.tl) (ss1.tr - ss1.br)
* (ss1.br - ss1.bl) (ss1.tl - ss1.bl)
* (ss1.br - ss1.bl) (ss1.tr - ss1.br)
*
* and add another set of two more subspans if in 16-pixel dispatch mode.
*
* For DDX, it ends up being easy: width = 2, horiz=0 gets us the same result
* for each pair, and vertstride = 2 jumps us 2 elements after processing a
* pair. But for DDY, it's harder, as we want to produce the pairs swizzled
* between each other. We could probably do it like ddx and swizzle the right
* order later, but bail for now and just produce
* ((ss0.tl - ss0.bl)x4 (ss1.tl - ss1.bl)x4)
*/
void
fs_visitor::generate_ddx(fs_inst *inst, struct brw_reg dst, struct brw_reg src)
{
struct brw_reg src0 = brw_reg(src.file, src.nr, 1,
BRW_REGISTER_TYPE_F,
BRW_VERTICAL_STRIDE_2,
BRW_WIDTH_2,
BRW_HORIZONTAL_STRIDE_0,
BRW_SWIZZLE_XYZW, WRITEMASK_XYZW);
struct brw_reg src1 = brw_reg(src.file, src.nr, 0,
BRW_REGISTER_TYPE_F,
BRW_VERTICAL_STRIDE_2,
BRW_WIDTH_2,
BRW_HORIZONTAL_STRIDE_0,
BRW_SWIZZLE_XYZW, WRITEMASK_XYZW);
brw_ADD(p, dst, src0, negate(src1));
}
void
fs_visitor::generate_ddy(fs_inst *inst, struct brw_reg dst, struct brw_reg src)
{
struct brw_reg src0 = brw_reg(src.file, src.nr, 0,
BRW_REGISTER_TYPE_F,
BRW_VERTICAL_STRIDE_4,
BRW_WIDTH_4,
BRW_HORIZONTAL_STRIDE_0,
BRW_SWIZZLE_XYZW, WRITEMASK_XYZW);
struct brw_reg src1 = brw_reg(src.file, src.nr, 2,
BRW_REGISTER_TYPE_F,
BRW_VERTICAL_STRIDE_4,
BRW_WIDTH_4,
BRW_HORIZONTAL_STRIDE_0,
BRW_SWIZZLE_XYZW, WRITEMASK_XYZW);
brw_ADD(p, dst, src0, negate(src1));
}
void
fs_visitor::generate_discard(fs_inst *inst)
{
@ -1795,6 +1860,12 @@ fs_visitor::generate_code()
case FS_OPCODE_DISCARD:
generate_discard(inst);
break;
case FS_OPCODE_DDX:
generate_ddx(inst, dst, src[0]);
break;
case FS_OPCODE_DDY:
generate_ddy(inst, dst, src[0]);
break;
case FS_OPCODE_FB_WRITE:
generate_fb_write(inst);
break;