From eae4c50be9607caac5ceadd132888e1905a2d3c3 Mon Sep 17 00:00:00 2001
From: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Date: Sun, 22 Sep 2024 16:00:16 -0400
Subject: [PATCH] agx: add spilling debug helpers

I keep typing these

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/31532>
---
 src/asahi/compiler/agx_register_allocate.c | 16 ++++++++++++++++
 src/asahi/compiler/agx_spill.c             |  6 ++++++
 2 files changed, 22 insertions(+)

diff --git a/src/asahi/compiler/agx_register_allocate.c b/src/asahi/compiler/agx_register_allocate.c
index b68edaab82a..ac4cc97bb29 100644
--- a/src/asahi/compiler/agx_register_allocate.c
+++ b/src/asahi/compiler/agx_register_allocate.c
@@ -151,6 +151,13 @@ agx_split_width(const agx_instr *I)
 static unsigned
 agx_calc_register_demand(agx_context *ctx)
 {
+   /* Print detailed demand calculation, helpful to debug spilling */
+   bool debug = false;
+
+   if (debug) {
+      agx_print_shader(ctx, stdout);
+   }
+
    uint8_t *widths = calloc(ctx->alloc, sizeof(uint8_t));
    enum ra_class *classes = calloc(ctx->alloc, sizeof(enum ra_class));
 
@@ -201,6 +208,10 @@ agx_calc_register_demand(agx_context *ctx)
        */
       unsigned late_kill_count = 0;
 
+      if (debug) {
+         printf("\n");
+      }
+
       agx_foreach_instr_in_block(block, I) {
          /* Phis happen in parallel and are already accounted for in the live-in
           * set, just skip them so we don't double count.
@@ -208,6 +219,11 @@ agx_calc_register_demand(agx_context *ctx)
          if (I->op == AGX_OPCODE_PHI)
             continue;
 
+         if (debug) {
+            printf("%u: ", demand);
+            agx_print_instr(I, stdout);
+         }
+
          if (I->op == AGX_OPCODE_PRELOAD) {
             unsigned size = agx_size_align_16(I->src[0].size);
             max_demand = MAX2(max_demand, I->src[0].value + size);
diff --git a/src/asahi/compiler/agx_spill.c b/src/asahi/compiler/agx_spill.c
index 5b4dfa8b74e..f8c1a4c0c7e 100644
--- a/src/asahi/compiler/agx_spill.c
+++ b/src/asahi/compiler/agx_spill.c
@@ -683,6 +683,12 @@ min_algorithm(struct spill_ctx *ctx)
    agx_foreach_instr_in_block(ctx->block, I) {
       assert(ctx->nW <= ctx->k && "invariant");
 
+      /* Debug to check against our RA demand calculations */
+      if (0) {
+         printf("%u: ", ctx->nW);
+         agx_print_instr(I, stdout);
+      }
+
       /* Phis are special since they happen along the edge. When we initialized
        * W and S, we implicitly chose which phis are spilled. So, here we just
        * need to rewrite the phis to write into memory.