commit 73e734bea5e84b712b4ced2bedbcf2e51c4a2fd4
author Chih-Hung Hsieh <chh@google.com> Tue Feb 24 16:06:15 2015 -0800
committer Chih-Hung Hsieh <chh@google.com> Mon Mar 02 16:50:39 2015 -0800
tree eb9eb44337d9496f55dd01c86d5e91fbd137e6be
parent 4eec22a6627927aaa11a67e3e18d36534af81856

Disable tail call optimization and use -mstackrealign to boot up on fugu.

http://llvm.org/bugs/show_bug.cgi?id=15086,
llvm tail call optimization is wrong for x86.

For Android/x86 to use SSE* instructions safely, stack should be 16-byte
aligned before JNI function call, which isn't true for all x86 device,
so -mstackrealign should be the default.

BUG: 19234330
Change-Id: I4c6676366788772dbe64fd7f0dd33b3ed5c9b80e

core/clang/TARGET_x86.mk

diff --git a/core/clang/TARGET_x86.mk b/core/clang/TARGET_x86.mk
index a6b2a6f..3ba34ae 100644
--- a/core/clang/TARGET_x86.mk
+++ b/core/clang/TARGET_x86.mk
@@ -18,7 +18,15 @@
   $(CLANG_CONFIG_EXTRA_CFLAGS) \
   $(CLANG_CONFIG_TARGET_EXTRA_CFLAGS) \
   $(CLANG_CONFIG_x86_EXTRA_CFLAGS) \
-  $(CLANG_CONFIG_x86_TARGET_EXTRA_ASFLAGS)
+  $(CLANG_CONFIG_x86_TARGET_EXTRA_ASFLAGS) \
+  -fno-optimize-sibling-calls \
+  -mstackrealign
+
+# http://llvm.org/bugs/show_bug.cgi?id=15086,
+# llvm tail call optimization is wrong for x86.
+# -mstackrealign is needed to realign stack in native code
+# that could be called from JNI, so that movaps instruction
+# will work on assumed stack aligned local variables.
 
 CLANG_CONFIG_x86_TARGET_EXTRA_CONLYFLAGS := \
   $(CLANG_CONFIG_EXTRA_CONLYFLAGS) \