commit 4432df12e1769ceb8967dab21b5af3067234f066
author Nicolas Capens <capn@google.com> Wed Jun 12 11:10:07 2019 -0400
committer Nicolas Capens <nicolascapens@google.com> Wed Jun 12 19:52:02 2019 +0000
tree 0778e920f7bd797d47d8f3c11c7c7f4f8b4d620a
parent f9411ce30f132dbcb297a533525000a788b7c951

Fix GCC inline assembly syntax

The output registers and memory clobber were not being properly
specified, which can cause incorrect compiler transformations when these
functions are inlined cross-module via ThinLTO.

Bug: b/135066502
Change-Id: I7031d5df2d9fe0f2712e65b98cfdf5b0990db598
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/32748
Presubmit-Ready: Nicolas Capens <nicolascapens@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Tested-by: Nicolas Capens <nicolascapens@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>

src/Common/Memory.cpp

diff --git a/src/Common/Memory.cpp b/src/Common/Memory.cpp
index 779d068..e7d4ac7 100644
--- a/src/Common/Memory.cpp
+++ b/src/Common/Memory.cpp
@@ -137,7 +137,7 @@
 	#if defined(_MSC_VER) && defined(__x86__) && !defined(MEMORY_SANITIZER)
 		__stosw(memory, element, count);
 	#elif defined(__GNUC__) && defined(__x86__) && !defined(MEMORY_SANITIZER)
-		__asm__("rep stosw" : : "D"(memory), "a"(element), "c"(count));
+		__asm__ __volatile__("rep stosw" : "+D"(memory), "+c"(count) : "a"(element) : "memory");
 	#else
 		for(size_t i = 0; i < count; i++)
 		{
@@ -151,7 +151,7 @@
 	#if defined(_MSC_VER) && defined(__x86__) && !defined(MEMORY_SANITIZER)
 		__stosd((unsigned long*)memory, element, count);
 	#elif defined(__GNUC__) && defined(__x86__) && !defined(MEMORY_SANITIZER)
-		__asm__("rep stosl" : : "D"(memory), "a"(element), "c"(count));
+		__asm__ __volatile__("rep stosl" : "+D"(memory), "+c"(count) : "a"(element) : "memory");
 	#else
 		for(size_t i = 0; i < count; i++)
 		{
@@ -159,4 +159,5 @@
 		}
 	#endif
 }
+
 }

src/System/Memory.cpp

diff --git a/src/System/Memory.cpp b/src/System/Memory.cpp
index ffaab71..663732f 100644
--- a/src/System/Memory.cpp
+++ b/src/System/Memory.cpp
@@ -137,7 +137,7 @@
 	#if defined(_MSC_VER) && defined(__x86__) && !defined(MEMORY_SANITIZER)
 		__stosw(memory, element, count);
 	#elif defined(__GNUC__) && defined(__x86__) && !defined(MEMORY_SANITIZER)
-		__asm__("rep stosw" : : "D"(memory), "a"(element), "c"(count));
+		__asm__ __volatile__("rep stosw" : "+D"(memory), "+c"(count) : "a"(element) : "memory");
 	#else
 		for(size_t i = 0; i < count; i++)
 		{
@@ -151,7 +151,7 @@
 	#if defined(_MSC_VER) && defined(__x86__) && !defined(MEMORY_SANITIZER)
 		__stosd((unsigned long*)memory, element, count);
 	#elif defined(__GNUC__) && defined(__x86__) && !defined(MEMORY_SANITIZER)
-		__asm__("rep stosl" : : "D"(memory), "a"(element), "c"(count));
+		__asm__ __volatile__("rep stosl" : "+D"(memory), "+c"(count) : "a"(element) : "memory");
 	#else
 		for(size_t i = 0; i < count; i++)
 		{