From 6f790b285c550e70d2891cdec79184abe3134fa6 Mon Sep 17 00:00:00 2001
From: Shokunin <30949000+tetrisgm@users.noreply.github.com>
Date: Mon, 5 Oct 2026 19:16:11 -0700
Subject: [PATCH] Skip PGXP counters on vertex probes instead of copying them

pgxp_probe_precise_vertex runs once per rectangle corner on the GPU
path and saved and restored the whole PGXPStats record around each
call. The shared lookup already knows it is a probe; let it skip the
counters. The test now walks the value-mismatch and tolerance-reject
branches too.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 runtime/src/pgxp.cpp        | 29 ++++++++++++++++-------------
 runtime/tests/test_pgxp.cpp |  9 ++++++++-
 2 files changed, 24 insertions(+), 14 deletions(-)

diff --git a/runtime/src/pgxp.cpp b/runtime/src/pgxp.cpp
index 0d4730a7..6cf80111 100644
--- a/runtime/src/pgxp.cpp
+++ b/runtime/src/pgxp.cpp
@@ -1093,7 +1093,11 @@ static int pgxp_get_precise_vertex_impl(uint32_t addr, uint32_t packet_word,
                                         int32_t int_x, int32_t int_y,
                                         int32_t *x16, int32_t *y16,
                                         uint16_t *sz, int probe) {
-    s_stats.lookups++;
+    /* A probe asks the same question without recording it (the rectangle
+     * shortcut runs one per corner before drawing): it skips every counter
+     * instead of copying the whole statistics record around the call. */
+    const int count = !probe;
+    if (count) s_stats.lookups++;
 
     int32_t px = 0, py = 0;
     uint16_t pz = 0;
@@ -1108,7 +1112,7 @@ static int pgxp_get_precise_vertex_impl(uint32_t addr, uint32_t packet_word,
                 py = pv->y16;
                 pz = (pv->flags & PGXP_F_VZ) ? pv->z : 0;
                 have = PGXP_SRC_DATAFLOW;
-            } else {
+            } else if (count) {
                 s_stats.value_mismatch++;
             }
         }
@@ -1135,25 +1139,27 @@ static int pgxp_get_precise_vertex_impl(uint32_t addr, uint32_t packet_word,
          * tolerance clamp. */
         const int why = pgxp_accept(px, py, int_x, int_y, packet_word);
         if (why == 1) {
-            s_stats.trunc_reject++;
+            if (count) s_stats.trunc_reject++;
             have = 0;
         } else if (why == 2) {
-            s_stats.tolerance_reject++;
+            if (count) s_stats.tolerance_reject++;
             have = 0;
         }
     }
 
     if (!have) {
-        s_stats.native++;
+        if (count) s_stats.native++;
         *x16 = int_x << 16;
         *y16 = int_y << 16;
         *sz = 0;
         return PGXP_SRC_NATIVE;
     }
 
-    if (have == PGXP_SRC_DATAFLOW) s_stats.dataflow_hit++;
-    else                           s_stats.fallback_hit++;
-    if (pz != 0) s_stats.w_valid++;
+    if (count) {
+        if (have == PGXP_SRC_DATAFLOW) s_stats.dataflow_hit++;
+        else                           s_stats.fallback_hit++;
+        if (pz != 0) s_stats.w_valid++;
+    }
     *x16 = px;
     *y16 = py;
     *sz = pz;
@@ -1170,13 +1176,10 @@ extern "C" int pgxp_get_precise_vertex(uint32_t addr, uint32_t packet_word,
 
 extern "C" int pgxp_probe_precise_vertex(uint32_t addr, uint32_t packet_word,
                                          int32_t int_x, int32_t int_y) {
-    const PGXPStats saved = s_stats;
     int32_t x16, y16;
     uint16_t sz;
-    const int src = pgxp_get_precise_vertex_impl(addr, packet_word, int_x, int_y,
-                                                 &x16, &y16, &sz, 1);
-    s_stats = saved;
-    return src;
+    return pgxp_get_precise_vertex_impl(addr, packet_word, int_x, int_y,
+                                        &x16, &y16, &sz, 1);
 }
 
 /* ------------------------------------------------------------------------- */
diff --git a/runtime/tests/test_pgxp.cpp b/runtime/tests/test_pgxp.cpp
index a0221f8b..5df1c67a 100644
--- a/runtime/tests/test_pgxp.cpp
+++ b/runtime/tests/test_pgxp.cpp
@@ -596,7 +596,14 @@ int main(void) {
         CHECK(pgxp_probe_precise_vertex(ADDR_A, PACKED, 160, 80) ==
               PGXP_SRC_DATAFLOW);
         CHECK(pgxp_probe_precise_vertex(ADDR_A, PACKED, 161, 80) ==
-              PGXP_SRC_NATIVE);
+              PGXP_SRC_NATIVE);                /* truncation reject */
+        CHECK(pgxp_probe_precise_vertex(ADDR_A, PACKED ^ 1u, 160, 80) ==
+              PGXP_SRC_NATIVE);                /* value mismatch */
+        const float tolerance_was = pgxp_tolerance();
+        pgxp_set_tolerance(0.1f);
+        CHECK(pgxp_probe_precise_vertex(ADDR_A, PACKED, 160, 80) ==
+              PGXP_SRC_NATIVE);                /* tolerance reject */
+        pgxp_set_tolerance(tolerance_was);
         pgxp_get_stats(&b);
         CHECK(std::memcmp(&a, &b, sizeof a) == 0);
         pgxp_note_rect_bypass(1);