Thanks Curro! I have tested this with our fp64 branch in BDW and it works fine. FWIW, I also tested it in IVB with shader.py and did not see any regressions, so we will include it in our branch.
Iago On Tue, 2016-05-03 at 21:26 -0700, Francisco Jerez wrote: > Instead of using the LOAD_PAYLOAD instruction (emitted through the > emit_transpose() helper that is no longer useful and this commit > removes) which had to be marked force_writemask_all in some cases, > emit a series of moves to apply proper channel enable signals to the > destination. Until now lower_simd_width() had mainly been used to > lower things that invariably had a basic block-local temporary as > destination so it didn't seem like a big deal, but I found it to be > the reason for several Piglit regressions in my SIMD32 branch and > Igalia discovered the same issue independently while working on FP64 > support. > --- > This is taken from the following WIP series: > https://cgit.freedesktop.org/~currojerez/mesa/log/?h=i965-late-simd-lowering > > See also: > https://lists.freedesktop.org/archives/mesa-dev/2016-May/115596.html > > src/mesa/drivers/dri/i965/brw_fs.cpp | 58 > +++++++++++------------------------- > 1 file changed, 18 insertions(+), 40 deletions(-) > > diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp > b/src/mesa/drivers/dri/i965/brw_fs.cpp > index 4b6aa67..34599cb 100644 > --- a/src/mesa/drivers/dri/i965/brw_fs.cpp > +++ b/src/mesa/drivers/dri/i965/brw_fs.cpp > @@ -4625,29 +4625,6 @@ get_lowered_simd_width(const struct brw_device_info > *devinfo, > } > } > > -/** > - * The \p rows array of registers represents a \p num_rows by \p num_columns > - * matrix in row-major order, write it in column-major order into the > register > - * passed as destination. \p stride gives the separation between matrix > - * elements in the input in fs_builder::dispatch_width() units. > - */ > -static void > -emit_transpose(const fs_builder &bld, > - const fs_reg &dst, const fs_reg *rows, > - unsigned num_rows, unsigned num_columns, unsigned stride) > -{ > - fs_reg *const components = new fs_reg[num_rows * num_columns]; > - > - for (unsigned i = 0; i < num_columns; ++i) { > - for (unsigned j = 0; j < num_rows; ++j) > - components[num_rows * i + j] = offset(rows[j], bld, stride * i); > - } > - > - bld.LOAD_PAYLOAD(dst, components, num_rows * num_columns, 0); > - > - delete[] components; > -} > - > bool > fs_visitor::lower_simd_width() > { > @@ -4698,16 +4675,19 @@ fs_visitor::lower_simd_width() > if (inst->src[j].file != BAD_FILE && > !is_uniform(inst->src[j])) { > /* Get the i-th copy_width-wide chunk of the source. */ > - const fs_reg src = horiz_offset(inst->src[j], copy_width * > i); > + const fs_builder cbld = lbld.group(copy_width, 0); > + const fs_reg src = offset(inst->src[j], cbld, i); > const unsigned src_size = inst->components_read(j); > > - /* Use a trivial transposition to copy one every n > - * copy_width-wide components of the register into a > - * temporary passed as source to the lowered instruction. > + /* Copy one every n copy_width-wide components of the > + * register into a temporary passed as source to the > lowered > + * instruction. > */ > split_inst.src[j] = lbld.vgrf(inst->src[j].type, src_size); > - emit_transpose(lbld.group(copy_width, 0), > - split_inst.src[j], &src, 1, src_size, n); > + > + for (unsigned k = 0; k < src_size; ++k) > + cbld.MOV(offset(split_inst.src[j], lbld, k), > + offset(src, cbld, n * k)); > } > } > > @@ -4726,20 +4706,18 @@ fs_visitor::lower_simd_width() > } > > if (inst->regs_written) { > - /* Distance between useful channels in the temporaries, skipping > - * garbage if the lowered instruction is wider than the original. > - */ > - const unsigned m = lower_width / copy_width; > + const fs_builder lbld = ibld.group(lower_width, 0); > > /* Interleave the components of the result from the lowered > - * instructions. We need to set exec_all() when copying more > than > - * one half per component, because LOAD_PAYLOAD (in terms of > which > - * emit_transpose is implemented) can only use the same channel > - * enable signals for all of its non-header sources. > + * instructions. > */ > - emit_transpose(ibld.exec_all(inst->exec_size > copy_width) > - .group(copy_width, 0), > - inst->dst, dsts, n, dst_size, m); > + for (unsigned i = 0; i < dst_size; ++i) { > + for (unsigned j = 0; j < n; ++j) { > + const fs_builder cbld = ibld.group(copy_width, j); > + cbld.MOV(offset(inst->dst, cbld, n * i + j), > + offset(dsts[j], lbld, i)); > + } > + } > } > > inst->remove(block); _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
