From 23d4fb3362409bcbbb2298fe58e51d15ffa81d2c Mon Sep 17 00:00:00 2001
From: James Zern <jzern@google.com>
Date: Thu, 17 Jul 2014 17:48:42 -0700
Subject: [PATCH] dsp/lossless: workaround gcc-4.9 bug on arm

force Sub3() to not be inlined, otherwise the code in Select() will be
incorrect.
https://android-review.googlesource.com/#/c/102511

(cherry picked from commit 637b3888090dea7d79aa51731186938f8f0edf4d)

Change-Id: I90ae58bf3e6cc92ca9897f69974733d562e29aaf
---
 src/dsp/lossless.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/dsp/lossless.c b/src/dsp/lossless.c
index 57d54a29..a1bf3584 100644
--- a/src/dsp/lossless.c
+++ b/src/dsp/lossless.c
@@ -450,12 +450,21 @@ static WEBP_INLINE uint32_t ClampedAddSubtractHalf(uint32_t c0, uint32_t c1,
   return ((uint32_t)a << 24) | (r << 16) | (g << 8) | b;
 }
 
-static WEBP_INLINE int Sub3(int a, int b, int c) {
+// gcc-4.9 on ARM generates incorrect code in Select() when Sub3() is inlined.
+#if defined(__arm__) && LOCAL_GCC_VERSION == 0x409
+# define LOCAL_INLINE __attribute__ ((noinline))
+#else
+# define LOCAL_INLINE WEBP_INLINE
+#endif
+
+static LOCAL_INLINE int Sub3(int a, int b, int c) {
   const int pb = b - c;
   const int pa = a - c;
   return abs(pb) - abs(pa);
 }
 
+#undef LOCAL_INLINE
+
 static WEBP_INLINE uint32_t Select(uint32_t a, uint32_t b, uint32_t c) {
   const int pa_minus_pb =
       Sub3((a >> 24)       , (b >> 24)       , (c >> 24)       ) +