From: Alex Hornung <ahornung@gmail.com>
Date: Wed, 18 Nov 2009 19:54:13 +0000 (+0000)
Subject: atomic - fix inline assembly
X-Git-Tag: v2.7.1~373^2~5
X-Git-Url: https://gitweb.dragonflybsd.org/dragonfly.git/commitdiff_plain/caae4d604234d17dff3080f60624a583965c2cf4?hp=8a1bf2ada1b31653599a6ce9a52bb4f40cc8307a

atomic - fix inline assembly

* Mark eax as early clobber in atomic_intr_cond_try. This solves a
  longstanding and previously conditionalized issue with clang.
  Marking it as early clobber avoids it being used as a register
  elsewhere, apart from explicit uses.
  GCC behaviour is not affected.

Suggested-by: Dale Johannesen <dalej@apple.com>
---

diff --git a/sys/cpu/i386/include/atomic.h b/sys/cpu/i386/include/atomic.h
index 34fd431549..0960c75371 100644
--- a/sys/cpu/i386/include/atomic.h
+++ b/sys/cpu/i386/include/atomic.h
@@ -309,12 +309,8 @@ atomic_intr_cond_try(__atomic_intr_t *p)
 			 MPLOCKED "decl %0; "			\
 			 "movl $1,%%eax;"			\
 			 "2: ;"
-			 : "+m" (*p), "=a"(ret)
-#ifdef __clang__
-                         : : "ax", "cx", "dx");
-#else
+			 : "+m" (*p), "=&a"(ret)
                          : : "cx", "dx");
-#endif
 	return (ret);
 }
 
diff --git a/sys/cpu/x86_64/include/atomic.h b/sys/cpu/x86_64/include/atomic.h
index cc543d3408..b6d0b66e8f 100644
--- a/sys/cpu/x86_64/include/atomic.h
+++ b/sys/cpu/x86_64/include/atomic.h
@@ -331,12 +331,8 @@ atomic_intr_cond_try(__atomic_intr_t *p)
 			 MPLOCKED "decl %0; "			\
 			 "movl $1,%%eax;"			\
 			 "2: ;"
-			 : "+m" (*p), "=a"(ret)
-#ifdef __clang__
-                         : : "ax", "cx", "dx");
-#else
+			 : "+m" (*p), "=&a"(ret)
                          : : "cx", "dx");
-#endif
 	return (ret);
 }