Mesa (staging/21.3): aco: Fix how p_is_helper interacts with optimizations.

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Module: Mesa
Branch: staging/21.3
Commit: ca3f3318e47fd4326bcdb58d840d497b64f3afb5
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=ca3f3318e47fd4326bcdb58d840d497b64f3afb5

Author: Timur Kristóf <timur.kristof at gmail.com>
Date:   Thu Oct 28 15:48:19 2021 +0200

aco: Fix how p_is_helper interacts with optimizations.

p_is_helper doesn't have any operands, so ACO's value numbering and/or
the pre-RA optimizer could incorrectly recognize two such instructions
as the same.

This patch adds exec as an operand to p_is_helper in order to achieve
correct behavior.

Cc: mesa-stable
Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/5570
Signed-off-by: Timur Kristóf <timur.kristof at gmail.com>
Reviewed-by: Daniel Schürmann <daniel at schuermann.dev>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/13577>
(cherry picked from commit d80c7f3406b80ae684a709de57a9ef3d54a497b6)

---

 .pick_status.json                              | 2 +-
 src/amd/compiler/aco_instruction_selection.cpp | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/.pick_status.json b/.pick_status.json
index 531e72e2900..1929e8e2220 100644
--- a/.pick_status.json
+++ b/.pick_status.json
@@ -1138,7 +1138,7 @@
         "description": "aco: Fix how p_is_helper interacts with optimizations.",
         "nominated": true,
         "nomination_type": 0,
-        "resolution": 0,
+        "resolution": 1,
         "main_sha": null,
         "because_sha": null
     },
diff --git a/src/amd/compiler/aco_instruction_selection.cpp b/src/amd/compiler/aco_instruction_selection.cpp
index ebc8555d40d..c64fa763905 100644
--- a/src/amd/compiler/aco_instruction_selection.cpp
+++ b/src/amd/compiler/aco_instruction_selection.cpp
@@ -8702,7 +8702,7 @@ visit_intrinsic(isel_context* ctx, nir_intrinsic_instr* instr)
       /* load_helper() after demote() get lowered to is_helper().
        * Otherwise, these two behave the same. */
       Temp dst = get_ssa_temp(ctx, &instr->dest.ssa);
-      bld.pseudo(aco_opcode::p_is_helper, Definition(dst));
+      bld.pseudo(aco_opcode::p_is_helper, Definition(dst), Operand(exec, bld.lm));
       ctx->block->kind |= block_kind_needs_lowering;
       ctx->program->needs_exact = true;
       break;