gallium/ntt: Avoid referencing undefined channels of system values.

Fixes failure to compile the shader on the host with gl_NumWorkGroups (for
example) on virgl.

Reviewed-by: Gert Wollny <gert.wollny@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8488>
This commit is contained in:
Eric Anholt 2021-01-13 16:30:15 -08:00
parent 37363ef663
commit fea6446b30

View file

@ -437,6 +437,21 @@ ntt_get_alu_src(struct ntt_compile *c, nir_alu_instr *instr, int i)
return usrc; return usrc;
} }
/* Reswizzles a source so that the unset channels in the write mask still refer
* to one of the channels present in the write mask.
*/
static struct ureg_src
ntt_swizzle_for_write_mask(struct ureg_src src, uint32_t write_mask)
{
assert(write_mask);
int first_chan = ffs(write_mask) - 1;
return ureg_swizzle(src,
(write_mask & TGSI_WRITEMASK_X) ? TGSI_SWIZZLE_X : first_chan,
(write_mask & TGSI_WRITEMASK_Y) ? TGSI_SWIZZLE_Y : first_chan,
(write_mask & TGSI_WRITEMASK_Z) ? TGSI_SWIZZLE_Z : first_chan,
(write_mask & TGSI_WRITEMASK_W) ? TGSI_SWIZZLE_W : first_chan);
}
static struct ureg_dst * static struct ureg_dst *
ntt_get_ssa_def_decl(struct ntt_compile *c, nir_ssa_def *ssa) ntt_get_ssa_def_decl(struct ntt_compile *c, nir_ssa_def *ssa)
{ {
@ -1530,7 +1545,16 @@ ntt_emit_load_sysval(struct ntt_compile *c, nir_intrinsic_instr *instr)
{ {
gl_system_value sysval = nir_system_value_from_intrinsic(instr->intrinsic); gl_system_value sysval = nir_system_value_from_intrinsic(instr->intrinsic);
enum tgsi_semantic semantic = tgsi_get_sysval_semantic(sysval); enum tgsi_semantic semantic = tgsi_get_sysval_semantic(sysval);
ntt_store(c, &instr->dest, ureg_DECL_system_value(c->ureg, semantic, 0)); struct ureg_src sv = ureg_DECL_system_value(c->ureg, semantic, 0);
/* virglrenderer doesn't like references to channels of the sysval that
* aren't defined, even if they aren't really read. (GLSL compile fails on
* gl_NumWorkGroups.w, for example).
*/
uint32_t write_mask = BITSET_MASK(nir_dest_num_components(instr->dest));
sv = ntt_swizzle_for_write_mask(sv, write_mask);
ntt_store(c, &instr->dest, sv);
} }
static void static void