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authorNicolai Hähnle <[email protected]>2016-10-07 16:15:30 +0200
committerNicolai Hähnle <[email protected]>2016-10-12 18:50:10 +0200
commit63193b9cdeca4f5d0e91f90c0926a1565f6b0415 (patch)
tree2c84ba15ce3c004dab4ade2fa8acb2a1751da81c /src/mesa/state_tracker/st_glsl_to_tgsi.cpp
parentf5f3cadca3809952288e3726ed5fde22090dc61d (diff)
st/glsl_to_tgsi: disable on-the-fly peephole for 64-bit operations
This optimization is incorrect with 64-bit operations, because the channel-splitting logic in emit_asm ends up being applied twice to the source operands. A lucky coincidence of how the writemask test works resulted in this optimization basically never being applied anyway. As far as I can tell, the only case where it would (incorrectly) have been applied is something like dvec2 d; float x = (float)d.y; which nobody seems to have ever done. But the moral equivalent does occur in one of the component layout piglit test. Cc: [email protected] Reviewed-by: Edward O'Callaghan <[email protected]> Reviewed-by: Dave Airlie <[email protected]>
Diffstat (limited to 'src/mesa/state_tracker/st_glsl_to_tgsi.cpp')
-rw-r--r--src/mesa/state_tracker/st_glsl_to_tgsi.cpp4
1 files changed, 4 insertions, 0 deletions
diff --git a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
index 6a63e5c6ec0..dc20fe49c55 100644
--- a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
+++ b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
@@ -255,6 +255,7 @@ public:
ir_instruction *ir;
GLboolean cond_update;
bool saturate;
+ bool is_64bit_expanded;
st_src_reg sampler; /**< sampler register */
int sampler_base;
int sampler_array_size; /**< 1-based size of sampler array, 1 if not array */
@@ -670,6 +671,7 @@ glsl_to_tgsi_visitor::emit_asm(ir_instruction *ir, unsigned op,
inst->src[1] = src1;
inst->src[2] = src2;
inst->src[3] = src3;
+ inst->is_64bit_expanded = false;
inst->ir = ir;
inst->dead_mask = 0;
/* default to float, for paths where this is not initialized
@@ -790,6 +792,7 @@ glsl_to_tgsi_visitor::emit_asm(ir_instruction *ir, unsigned op,
dinst->prev = NULL;
}
this->instructions.push_tail(dinst);
+ dinst->is_64bit_expanded = true;
/* modify the destination if we are splitting */
for (j = 0; j < 2; j++) {
@@ -2908,6 +2911,7 @@ glsl_to_tgsi_visitor::visit(ir_assignment *ir)
} else if (ir->rhs->as_expression() &&
this->instructions.get_tail() &&
ir->rhs == ((glsl_to_tgsi_instruction *)this->instructions.get_tail())->ir &&
+ !((glsl_to_tgsi_instruction *)this->instructions.get_tail())->is_64bit_expanded &&
type_size(ir->lhs->type) == 1 &&
l.writemask == ((glsl_to_tgsi_instruction *)this->instructions.get_tail())->dst[0].writemask) {
/* To avoid emitting an extra MOV when assigning an expression to a