No shader-db changes, so perhaps adding a test on
test_fs_cmod_propagation? In any case, the patch looks good to me:
Reviewed-by: Alejandro Piñeiro <apinhe...@igalia.com>
On 14/09/18 00:06, Ian Romanick wrote:
> From: Ian Romanick <ian.d.roman...@intel.com>
>
> No shader-db changes on any Intel platform... which probably explains
> why no bugs have been bisected to this problem since it landed in Mesa
> 18.1. :( The commit mentioned below is in 18.2, so 18.1 would need a
> slightly different fix (due to code refactoring).
>
> Signed-off-by: Ian Romanick <ian.d.roman...@intel.com>
> Fixes: 77f269bb560 "i965/fs: Refactor propagation of conditional modifiers
> from compares to adds"
> Cc: Matt Turner <matts...@gmail.com> (reviewed the original patch)
> Cc: Alejandro Piñeiro <apinhe...@igalia.com> (reviewed the original patch)
> ---
> src/intel/compiler/brw_fs_cmod_propagation.cpp | 10 +++++++++-
> 1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/src/intel/compiler/brw_fs_cmod_propagation.cpp
> b/src/intel/compiler/brw_fs_cmod_propagation.cpp
> index 5b74f267359..5fb522f810f 100644
> --- a/src/intel/compiler/brw_fs_cmod_propagation.cpp
> +++ b/src/intel/compiler/brw_fs_cmod_propagation.cpp
> @@ -211,9 +211,17 @@ opt_cmod_propagation_local(const gen_device_info
> *devinfo, bblock_t *block)
> /* A CMP with a second source of zero can match with anything. A CMP
> * with a second source that is not zero can only match with an ADD
> * instruction.
> + *
> + * Only apply this optimization to float-point sources. It can fail
> for
> + * integers. For inputs a = 0x80000000, b = 4, int(0x80000000) < 4,
> but
> + * int(0x80000000) - 4 overflows and results in 0x7ffffffc. that's not
> + * less than zero, so the flags get set differently than for (a < b).
> */
> if (inst->opcode == BRW_OPCODE_CMP && !inst->src[1].is_zero()) {
> - progress = cmod_propagate_cmp_to_add(devinfo, block, inst) ||
> progress;
> + if (brw_reg_type_is_floating_point(inst->src[0].type) &&
> + cmod_propagate_cmp_to_add(devinfo, block, inst))
> + progress = true;
> +
> continue;
> }
>
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