pan/midgard: Add mir_calculate_temp_count helper

This allows us to fill in ctx->temp_count explicitly, even if we haven't
squished down the MIR.

Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>

2 files changed, 19 insertions, 0 deletions

diff --git a/src/panfrost/midgard/compiler.h b/src/panfrost/midgard/compiler.h
index a338557a7a0..66cb34f9db5 100644
--- a/src/panfrost/midgard/compiler.h
+++ b/src/panfrost/midgard/compiler.h
@@ -525,6 +525,7 @@ bool mir_nontrivial_outmod(midgard_instruction *ins);
 void mir_insert_instruction_before_scheduled(compiler_context *ctx, midgard_block *block, midgard_instruction *tag, midgard_instruction ins);
 void mir_insert_instruction_after_scheduled(compiler_context *ctx, midgard_block *block, midgard_instruction *tag, midgard_instruction ins);
 void mir_flip(midgard_instruction *ins);
+void mir_compute_temp_count(compiler_context *ctx);
 
 /* MIR goodies */
 
diff --git a/src/panfrost/midgard/mir.c b/src/panfrost/midgard/mir.c
index f02527ff219..e19ed4f98a6 100644
--- a/src/panfrost/midgard/mir.c
+++ b/src/panfrost/midgard/mir.c
@@ -544,3 +544,21 @@ mir_flip(midgard_instruction *ins)
         ins->alu.src1 = ins->alu.src2;
         ins->alu.src2 = temp;
 }
+
+/* Before squashing, calculate ctx->temp_count just by observing the MIR */
+
+void
+mir_compute_temp_count(compiler_context *ctx)
+{
+        if (ctx->temp_count)
+                return;
+
+        unsigned max_dest = 0;
+
+        mir_foreach_instr_global(ctx, ins) {
+                if (ins->dest < SSA_FIXED_MINIMUM)
+                        max_dest = MAX2(max_dest, ins->dest);
+        }
+
+        ctx->temp_count = max_dest;
+}