From: Ian Romanick <idr@us.ibm.com>
Date: Mon, 18 Oct 2004 23:24:51 +0000 (+0000)
Subject: Small optimization for big-endian (e.g., PowerPC) systems.
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=f404ff7b76d70a495d4246851127125a194a1adf;p=mesa.git

Small optimization for big-endian (e.g., PowerPC) systems.
---

diff --git a/src/mesa/drivers/dri/common/spantmp2.h b/src/mesa/drivers/dri/common/spantmp2.h
index 6bdbe150c3b..5a161b11ddf 100644
--- a/src/mesa/drivers/dri/common/spantmp2.h
+++ b/src/mesa/drivers/dri/common/spantmp2.h
@@ -115,6 +115,16 @@
 				: "=r" (p) : "r" (p) );                 \
        ((GLuint *)rgba)[0] = p;                                         \
     } while (0)
+# elif defined( MESA_BIG_ENDIAN )
+    /* On PowerPC with GCC 3.4.2 the shift madness below becomes a single
+     * rotlwi instruction.  It also produces good code on SPARC.
+     */
+#  define READ_RGBA( rgba, _x, _y )				        \
+     do {								\
+        GLuint p = *(volatile GLuint *) GET_SRC_PTR(_x, _y);            \
+        GLuint t = p;                                                   \
+        *((uint32_t *) rgba) = (t >> 24) | (p << 8);                    \
+     } while (0)
 # else
 #  define READ_RGBA( rgba, _x, _y )				        \
      do {								\