/* 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)
*
* The negate_value boolean is used to negate the d/dy computation for FBOs,
* since they place the origin at the upper left instead of the lower left.
*/
void emit_ddxy(struct brw_compile *p,
const struct brw_reg *dst,
GLuint mask,
bool is_ddx,
const struct brw_reg *arg0,
bool negate_value)
{
int i;
struct brw_reg src0, src1;
if (mask & SATURATE)
brw_set_saturate(p, 1);
for (i = 0; i < 4; i++ ) {
if (mask & (1<<i)) {
if (is_ddx) {
src0 = brw_reg(arg0[i].file, arg0[i].nr, 1,
BRW_REGISTER_TYPE_F,
BRW_VERTICAL_STRIDE_2,
BRW_WIDTH_2,
BRW_HORIZONTAL_STRIDE_0,
BRW_SWIZZLE_XYZW, WRITEMASK_XYZW);
src1 = brw_reg(arg0[i].file, arg0[i].nr, 0,
BRW_REGISTER_TYPE_F,
BRW_VERTICAL_STRIDE_2,
BRW_WIDTH_2,
BRW_HORIZONTAL_STRIDE_0,
BRW_SWIZZLE_XYZW, WRITEMASK_XYZW);
} else {
src0 = brw_reg(arg0[i].file, arg0[i].nr, 0,
BRW_REGISTER_TYPE_F,
BRW_VERTICAL_STRIDE_4,
BRW_WIDTH_4,
BRW_HORIZONTAL_STRIDE_0,
BRW_SWIZZLE_XYZW, WRITEMASK_XYZW);
src1 = brw_reg(arg0[i].file, arg0[i].nr, 2,
BRW_REGISTER_TYPE_F,
BRW_VERTICAL_STRIDE_4,
BRW_WIDTH_4,
BRW_HORIZONTAL_STRIDE_0,
BRW_SWIZZLE_XYZW, WRITEMASK_XYZW);
}
if (negate_value)
brw_ADD(p, dst[i], src1, negate(src0));
else
brw_ADD(p, dst[i], src0, negate(src1));
}
}
if (mask & SATURATE)
brw_set_saturate(p, 0);
}
static inline struct brw_reg sample_result(int dw, int result)
{
return brw_reg(BRW_GENERAL_REGISTER_FILE, result, 0,
BRW_REGISTER_TYPE_UW,
dw == 16 ? BRW_VERTICAL_STRIDE_16 : BRW_VERTICAL_STRIDE_8,
dw == 16 ? BRW_WIDTH_16 : BRW_WIDTH_8,
BRW_HORIZONTAL_STRIDE_1,
BRW_SWIZZLE_XYZW,
WRITEMASK_XYZW);
}
static inline struct brw_reg null_result(int dw)
{
return brw_reg(BRW_ARCHITECTURE_REGISTER_FILE, BRW_ARF_NULL, 0,
BRW_REGISTER_TYPE_UW,
dw == 16 ? BRW_VERTICAL_STRIDE_16 : BRW_VERTICAL_STRIDE_8,
dw == 16 ? BRW_WIDTH_16 : BRW_WIDTH_8,
BRW_HORIZONTAL_STRIDE_1,
BRW_SWIZZLE_XYZW,
WRITEMASK_XYZW);
}
