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authorIago Toral Quiroga <[email protected]>2015-01-19 12:32:09 +0100
committerIago Toral Quiroga <[email protected]>2015-02-03 13:19:36 +0100
commit6dd346c2328df86f843c3a355a7919fb0404f6df (patch)
treead1a41101d354675228e871204a49b9094bfce7a /src
parent5b941ce8575089279b92797f7c10aa294cbc16c8 (diff)
i965: Fix negate with unsigned integers
For code such as: uint tmp1 = uint(in0); uint tmp2 = -tmp1; float out0 = float(tmp2); We produce code like: mov(8) g5<1>.xF -g9<4,4,1>.xUD which does not produce correct results. This code produces the results we would expect if tmp1 and tmp2 were signed integers instead. It seems that a similar problem was detected and addressed when using negations with unsigned integers as part of condionals, but it looks like the problem has a wider impact than that. This patch fixes the problem by preventing copy-propagation of negated UD registers in all scenarios, not only in conditionals. Fixes the following 24 dEQP tests: dEQP-GLES3.functional.shaders.operator.unary_operator.minus.*_uint_* dEQP-GLES3.functional.shaders.operator.unary_operator.minus.*_uvec2_* dEQP-GLES3.functional.shaders.operator.unary_operator.minus.*_uvec3_* dEQP-GLES3.functional.shaders.operator.unary_operator.minus.*_uvec4_* Reviewed-by: Anuj Phogat <[email protected]>
Diffstat (limited to 'src')
-rw-r--r--src/mesa/drivers/dri/i965/brw_fs_copy_propagation.cpp9
-rw-r--r--src/mesa/drivers/dri/i965/brw_vec4_copy_propagation.cpp9
2 files changed, 10 insertions, 8 deletions
diff --git a/src/mesa/drivers/dri/i965/brw_fs_copy_propagation.cpp b/src/mesa/drivers/dri/i965/brw_fs_copy_propagation.cpp
index 70f417fd2a8..5dd72559298 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_copy_propagation.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_copy_propagation.cpp
@@ -302,9 +302,12 @@ fs_visitor::try_copy_propagate(fs_inst *inst, int arg, acp_entry *entry)
(entry->dst.reg_offset + entry->regs_written) * 32)
return false;
- /* See resolve_ud_negate() and comment in brw_fs_emit.cpp. */
- if (inst->conditional_mod &&
- inst->src[arg].type == BRW_REGISTER_TYPE_UD &&
+ /* we can't generally copy-propagate UD negations because we
+ * can end up accessing the resulting values as signed integers
+ * instead. See also resolve_ud_negate() and comment in
+ * fs_generator::generate_code.
+ */
+ if (inst->src[arg].type == BRW_REGISTER_TYPE_UD &&
entry->src.negate)
return false;
diff --git a/src/mesa/drivers/dri/i965/brw_vec4_copy_propagation.cpp b/src/mesa/drivers/dri/i965/brw_vec4_copy_propagation.cpp
index bf15941e102..e25c9953c1c 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4_copy_propagation.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4_copy_propagation.cpp
@@ -314,12 +314,11 @@ try_copy_propagate(struct brw_context *brw, vec4_instruction *inst,
if (inst->is_send_from_grf())
return false;
- /* We can't copy-propagate a UD negation into a condmod
- * instruction, because the condmod ends up looking at the 33-bit
- * signed accumulator value instead of the 32-bit value we wanted
+ /* we can't generally copy-propagate UD negations becuse we
+ * end up accessing the resulting values as signed integers
+ * instead. See also resolve_ud_negate().
*/
- if (inst->conditional_mod &&
- value.negate &&
+ if (value.negate &&
value.type == BRW_REGISTER_TYPE_UD)
return false;