From: Brian Paul <brianp@vmware.com>
Date: Wed, 14 Sep 2016 18:16:18 +0000 (-0600)
Subject: mesa: check for no matrix change in _mesa_LoadMatrixf()
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=0d2eb8c14d8c791603cb60cb56ed468ee49543ad;p=mesa.git

mesa: check for no matrix change in _mesa_LoadMatrixf()

Some apps issue redundant glLoadMatrixf() calls with the same matrix.
Try to avoid setting dirty state in that situation.

This reduces the number of constant buffer updates by about half in
ET Quake Wars.

Tested with Piglit, ETQW, Sauerbraten, Google Earth, etc.

Reviewed-by: Charmaine Lee <charmainel@vmware.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
---

diff --git a/src/mesa/main/matrix.c b/src/mesa/main/matrix.c
index b30b983f14f..83f081e88e5 100644
--- a/src/mesa/main/matrix.c
+++ b/src/mesa/main/matrix.c
@@ -356,9 +356,11 @@ _mesa_LoadMatrixf( const GLfloat *m )
           m[2], m[6], m[10], m[14],
           m[3], m[7], m[11], m[15]);
 
-   FLUSH_VERTICES(ctx, 0);
-   _math_matrix_loadf( ctx->CurrentStack->Top, m );
-   ctx->NewState |= ctx->CurrentStack->DirtyFlag;
+   if (memcmp(m, ctx->CurrentStack->Top->m, 16 * sizeof(GLfloat)) != 0) {
+      FLUSH_VERTICES(ctx, 0);
+      _math_matrix_loadf( ctx->CurrentStack->Top, m );
+      ctx->NewState |= ctx->CurrentStack->DirtyFlag;
+   }
 }