diff options
| author | Jason Ekstrand <[email protected]> | 2015-04-13 14:13:16 -0700 |
|---|---|---|
| committer | Jason Ekstrand <[email protected]> | 2015-04-22 18:10:41 -0700 |
| commit | 125574d1effcb3e3eda93f2b2975bc6cc606df3e (patch) | |
| tree | fc560faf5adff7c42509c903c5c7a0f51e5a9428 | |
| parent | 296131f4674ee979a8cffe56fc61bbd42110982e (diff) | |
nir/lower_source_mods: Don't propagate register sources
The nir_lower_source_mods pass does a weak form of copy propagation to
clean up all of the mov-with-negate's that get generated. However, we
weren't properly checking that the sources were SSA and so we could end up
moving a register read which is not, in general, valid.
Reviewed-by: Connor Abbott <[email protected]>
| -rw-r--r-- | src/glsl/nir/nir_lower_to_source_mods.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/src/glsl/nir/nir_lower_to_source_mods.c b/src/glsl/nir/nir_lower_to_source_mods.c index d6bf77f17c1..7b4a0f65738 100644 --- a/src/glsl/nir/nir_lower_to_source_mods.c +++ b/src/glsl/nir/nir_lower_to_source_mods.c @@ -67,6 +67,13 @@ nir_lower_to_source_mods_block(nir_block *block, void *state) continue; } + /* We can only do a rewrite if the source we are copying is SSA. + * Otherwise, moving the read might invalidly reorder reads/writes + * on a register. + */ + if (!parent->src[0].src.is_ssa) + continue; + nir_instr_rewrite_src(instr, &alu->src[i].src, parent->src[0].src); if (alu->src[i].abs) { /* abs trumps both neg and abs, do nothing */ |