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@gmail.com>
Reviewed-by: Daniel Schürmann <daniel@schuermann.dev>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/13577>

diff --git a/src/amd/compiler/aco_instruction_selection.cpp b/src/amd/compiler/aco_instruction_selection.cpp
index 5a23c78..5b3d22c 100644 (file)
--- a/src/amd/compiler/aco_instruction_selection.cpp
+++ b/src/amd/compiler/aco_instruction_selection.cpp
@@ -8707,7 +8707,7 @@ 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;