418 lines
13 KiB
Diff
418 lines
13 KiB
Diff
From e0f6dec35f9286e78879fe1ac92803fd69fc4fdc Mon Sep 17 00:00:00 2001
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From: H. Peter Anvin <hpa@linux.intel.com>
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Date: Wed, 04 Dec 2013 22:31:28 +0000
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Subject: x86, bitops: Correct the assembly constraints to testing bitops
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In checkin:
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0c44c2d0f459 x86: Use asm goto to implement better modify_and_test() functions
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the various functions which do modify and test were unified and
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optimized using "asm goto". However, this change missed the detail
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that the bitops require an "Ir" constraint rather than an "er"
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constraint ("I" = integer constant from 0-31, "e" = signed 32-bit
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integer constant). This would cause code to miscompile if these
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functions were used on constant bit positions 32-255 and the build to
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fail if used on constant bit positions above 255.
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Add the constraints as a parameter to the GEN_BINARY_RMWcc() macro to
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avoid this problem.
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Reported-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
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Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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Cc: Peter Zijlstra <peterz@infradead.org>
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Link: http://lkml.kernel.org/r/529E8719.4070202@zytor.com
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---
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diff --git a/arch/x86/include/asm/atomic.h b/arch/x86/include/asm/atomic.h
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index da31c8b..b17f4f4 100644
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--- a/arch/x86/include/asm/atomic.h
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+++ b/arch/x86/include/asm/atomic.h
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@@ -77,7 +77,7 @@ static inline void atomic_sub(int i, atomic_t *v)
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*/
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static inline int atomic_sub_and_test(int i, atomic_t *v)
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{
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- GEN_BINARY_RMWcc(LOCK_PREFIX "subl", v->counter, i, "%0", "e");
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+ GEN_BINARY_RMWcc(LOCK_PREFIX "subl", v->counter, "er", i, "%0", "e");
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}
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/**
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@@ -141,7 +141,7 @@ static inline int atomic_inc_and_test(atomic_t *v)
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*/
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static inline int atomic_add_negative(int i, atomic_t *v)
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{
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- GEN_BINARY_RMWcc(LOCK_PREFIX "addl", v->counter, i, "%0", "s");
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+ GEN_BINARY_RMWcc(LOCK_PREFIX "addl", v->counter, "er", i, "%0", "s");
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}
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/**
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diff --git a/arch/x86/include/asm/atomic64_64.h b/arch/x86/include/asm/atomic64_64.h
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index 3f065c9..46e9052 100644
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--- a/arch/x86/include/asm/atomic64_64.h
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+++ b/arch/x86/include/asm/atomic64_64.h
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@@ -72,7 +72,7 @@ static inline void atomic64_sub(long i, atomic64_t *v)
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*/
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static inline int atomic64_sub_and_test(long i, atomic64_t *v)
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{
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- GEN_BINARY_RMWcc(LOCK_PREFIX "subq", v->counter, i, "%0", "e");
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+ GEN_BINARY_RMWcc(LOCK_PREFIX "subq", v->counter, "er", i, "%0", "e");
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}
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/**
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@@ -138,7 +138,7 @@ static inline int atomic64_inc_and_test(atomic64_t *v)
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*/
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static inline int atomic64_add_negative(long i, atomic64_t *v)
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{
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- GEN_BINARY_RMWcc(LOCK_PREFIX "addq", v->counter, i, "%0", "s");
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+ GEN_BINARY_RMWcc(LOCK_PREFIX "addq", v->counter, "er", i, "%0", "s");
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}
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/**
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diff --git a/arch/x86/include/asm/bitops.h b/arch/x86/include/asm/bitops.h
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index 6d76d09..9fc1af7 100644
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--- a/arch/x86/include/asm/bitops.h
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+++ b/arch/x86/include/asm/bitops.h
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@@ -205,7 +205,7 @@ static inline void change_bit(long nr, volatile unsigned long *addr)
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*/
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static inline int test_and_set_bit(long nr, volatile unsigned long *addr)
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{
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- GEN_BINARY_RMWcc(LOCK_PREFIX "bts", *addr, nr, "%0", "c");
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+ GEN_BINARY_RMWcc(LOCK_PREFIX "bts", *addr, "Ir", nr, "%0", "c");
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}
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/**
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@@ -251,7 +251,7 @@ static inline int __test_and_set_bit(long nr, volatile unsigned long *addr)
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*/
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static inline int test_and_clear_bit(long nr, volatile unsigned long *addr)
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{
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- GEN_BINARY_RMWcc(LOCK_PREFIX "btr", *addr, nr, "%0", "c");
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+ GEN_BINARY_RMWcc(LOCK_PREFIX "btr", *addr, "Ir", nr, "%0", "c");
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}
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/**
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@@ -304,7 +304,7 @@ static inline int __test_and_change_bit(long nr, volatile unsigned long *addr)
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*/
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static inline int test_and_change_bit(long nr, volatile unsigned long *addr)
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{
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- GEN_BINARY_RMWcc(LOCK_PREFIX "btc", *addr, nr, "%0", "c");
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+ GEN_BINARY_RMWcc(LOCK_PREFIX "btc", *addr, "Ir", nr, "%0", "c");
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}
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static __always_inline int constant_test_bit(long nr, const volatile unsigned long *addr)
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diff --git a/arch/x86/include/asm/local.h b/arch/x86/include/asm/local.h
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index 5b23e60..4ad6560 100644
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--- a/arch/x86/include/asm/local.h
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+++ b/arch/x86/include/asm/local.h
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@@ -52,7 +52,7 @@ static inline void local_sub(long i, local_t *l)
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*/
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static inline int local_sub_and_test(long i, local_t *l)
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{
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- GEN_BINARY_RMWcc(_ASM_SUB, l->a.counter, i, "%0", "e");
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+ GEN_BINARY_RMWcc(_ASM_SUB, l->a.counter, "er", i, "%0", "e");
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}
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/**
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@@ -92,7 +92,7 @@ static inline int local_inc_and_test(local_t *l)
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*/
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static inline int local_add_negative(long i, local_t *l)
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{
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- GEN_BINARY_RMWcc(_ASM_ADD, l->a.counter, i, "%0", "s");
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+ GEN_BINARY_RMWcc(_ASM_ADD, l->a.counter, "er", i, "%0", "s");
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}
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/**
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diff --git a/arch/x86/include/asm/rmwcc.h b/arch/x86/include/asm/rmwcc.h
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index 1ff990f..8f7866a 100644
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--- a/arch/x86/include/asm/rmwcc.h
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+++ b/arch/x86/include/asm/rmwcc.h
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@@ -16,8 +16,8 @@ cc_label: \
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#define GEN_UNARY_RMWcc(op, var, arg0, cc) \
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__GEN_RMWcc(op " " arg0, var, cc)
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-#define GEN_BINARY_RMWcc(op, var, val, arg0, cc) \
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- __GEN_RMWcc(op " %1, " arg0, var, cc, "er" (val))
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+#define GEN_BINARY_RMWcc(op, var, vcon, val, arg0, cc) \
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+ __GEN_RMWcc(op " %1, " arg0, var, cc, vcon (val))
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#else /* !CC_HAVE_ASM_GOTO */
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@@ -33,8 +33,8 @@ do { \
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#define GEN_UNARY_RMWcc(op, var, arg0, cc) \
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__GEN_RMWcc(op " " arg0, var, cc)
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-#define GEN_BINARY_RMWcc(op, var, val, arg0, cc) \
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- __GEN_RMWcc(op " %2, " arg0, var, cc, "er" (val))
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+#define GEN_BINARY_RMWcc(op, var, vcon, val, arg0, cc) \
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+ __GEN_RMWcc(op " %2, " arg0, var, cc, vcon (val))
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#endif /* CC_HAVE_ASM_GOTO */
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--
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cgit v0.9.2
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From 0c44c2d0f459cd7e275242b72f500137c4fa834d Mon Sep 17 00:00:00 2001
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From: Peter Zijlstra <peterz@infradead.org>
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Date: Wed, 11 Sep 2013 13:19:24 +0000
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Subject: x86: Use asm goto to implement better modify_and_test() functions
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Linus suggested using asm goto to get rid of the typical SETcc + TEST
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instruction pair -- which also clobbers an extra register -- for our
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typical modify_and_test() functions.
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Because asm goto doesn't allow output fields it has to include an
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unconditinal memory clobber when it changes a memory variable to force
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a reload.
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Luckily all atomic ops already imply a compiler barrier to go along
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with their memory barrier semantics.
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Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
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Signed-off-by: Peter Zijlstra <peterz@infradead.org>
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Link: http://lkml.kernel.org/n/tip-0mtn9siwbeo1d33bap1422se@git.kernel.org
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Signed-off-by: Ingo Molnar <mingo@kernel.org>
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---
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diff --git a/arch/x86/include/asm/atomic.h b/arch/x86/include/asm/atomic.h
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index 722aa3b..da31c8b 100644
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--- a/arch/x86/include/asm/atomic.h
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+++ b/arch/x86/include/asm/atomic.h
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@@ -6,6 +6,7 @@
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#include <asm/processor.h>
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#include <asm/alternative.h>
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#include <asm/cmpxchg.h>
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+#include <asm/rmwcc.h>
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/*
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* Atomic operations that C can't guarantee us. Useful for
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@@ -76,12 +77,7 @@ static inline void atomic_sub(int i, atomic_t *v)
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*/
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static inline int atomic_sub_and_test(int i, atomic_t *v)
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{
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- unsigned char c;
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-
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- asm volatile(LOCK_PREFIX "subl %2,%0; sete %1"
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- : "+m" (v->counter), "=qm" (c)
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- : "ir" (i) : "memory");
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- return c;
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+ GEN_BINARY_RMWcc(LOCK_PREFIX "subl", v->counter, i, "%0", "e");
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}
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/**
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@@ -118,12 +114,7 @@ static inline void atomic_dec(atomic_t *v)
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*/
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static inline int atomic_dec_and_test(atomic_t *v)
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{
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- unsigned char c;
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-
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- asm volatile(LOCK_PREFIX "decl %0; sete %1"
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- : "+m" (v->counter), "=qm" (c)
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- : : "memory");
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- return c != 0;
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+ GEN_UNARY_RMWcc(LOCK_PREFIX "decl", v->counter, "%0", "e");
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}
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/**
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@@ -136,12 +127,7 @@ static inline int atomic_dec_and_test(atomic_t *v)
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*/
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static inline int atomic_inc_and_test(atomic_t *v)
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{
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- unsigned char c;
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-
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- asm volatile(LOCK_PREFIX "incl %0; sete %1"
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- : "+m" (v->counter), "=qm" (c)
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- : : "memory");
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- return c != 0;
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+ GEN_UNARY_RMWcc(LOCK_PREFIX "incl", v->counter, "%0", "e");
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}
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/**
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@@ -155,12 +141,7 @@ static inline int atomic_inc_and_test(atomic_t *v)
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*/
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static inline int atomic_add_negative(int i, atomic_t *v)
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{
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- unsigned char c;
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-
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- asm volatile(LOCK_PREFIX "addl %2,%0; sets %1"
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- : "+m" (v->counter), "=qm" (c)
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- : "ir" (i) : "memory");
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- return c;
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+ GEN_BINARY_RMWcc(LOCK_PREFIX "addl", v->counter, i, "%0", "s");
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}
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/**
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diff --git a/arch/x86/include/asm/atomic64_64.h b/arch/x86/include/asm/atomic64_64.h
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index 0e1cbfc..3f065c9 100644
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--- a/arch/x86/include/asm/atomic64_64.h
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+++ b/arch/x86/include/asm/atomic64_64.h
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@@ -72,12 +72,7 @@ static inline void atomic64_sub(long i, atomic64_t *v)
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*/
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static inline int atomic64_sub_and_test(long i, atomic64_t *v)
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{
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- unsigned char c;
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-
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- asm volatile(LOCK_PREFIX "subq %2,%0; sete %1"
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- : "=m" (v->counter), "=qm" (c)
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- : "er" (i), "m" (v->counter) : "memory");
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- return c;
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+ GEN_BINARY_RMWcc(LOCK_PREFIX "subq", v->counter, i, "%0", "e");
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}
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/**
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@@ -116,12 +111,7 @@ static inline void atomic64_dec(atomic64_t *v)
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*/
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static inline int atomic64_dec_and_test(atomic64_t *v)
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{
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- unsigned char c;
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-
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- asm volatile(LOCK_PREFIX "decq %0; sete %1"
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- : "=m" (v->counter), "=qm" (c)
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- : "m" (v->counter) : "memory");
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- return c != 0;
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+ GEN_UNARY_RMWcc(LOCK_PREFIX "decq", v->counter, "%0", "e");
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}
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/**
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@@ -134,12 +124,7 @@ static inline int atomic64_dec_and_test(atomic64_t *v)
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*/
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static inline int atomic64_inc_and_test(atomic64_t *v)
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{
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- unsigned char c;
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-
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- asm volatile(LOCK_PREFIX "incq %0; sete %1"
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- : "=m" (v->counter), "=qm" (c)
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- : "m" (v->counter) : "memory");
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- return c != 0;
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+ GEN_UNARY_RMWcc(LOCK_PREFIX "incq", v->counter, "%0", "e");
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}
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/**
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@@ -153,12 +138,7 @@ static inline int atomic64_inc_and_test(atomic64_t *v)
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*/
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static inline int atomic64_add_negative(long i, atomic64_t *v)
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{
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- unsigned char c;
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-
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- asm volatile(LOCK_PREFIX "addq %2,%0; sets %1"
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- : "=m" (v->counter), "=qm" (c)
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- : "er" (i), "m" (v->counter) : "memory");
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- return c;
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+ GEN_BINARY_RMWcc(LOCK_PREFIX "addq", v->counter, i, "%0", "s");
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}
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/**
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diff --git a/arch/x86/include/asm/bitops.h b/arch/x86/include/asm/bitops.h
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index 41639ce..6d76d09 100644
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--- a/arch/x86/include/asm/bitops.h
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+++ b/arch/x86/include/asm/bitops.h
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@@ -14,6 +14,7 @@
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#include <linux/compiler.h>
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#include <asm/alternative.h>
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+#include <asm/rmwcc.h>
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#if BITS_PER_LONG == 32
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# define _BITOPS_LONG_SHIFT 5
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@@ -204,12 +205,7 @@ static inline void change_bit(long nr, volatile unsigned long *addr)
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*/
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static inline int test_and_set_bit(long nr, volatile unsigned long *addr)
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{
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- int oldbit;
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-
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- asm volatile(LOCK_PREFIX "bts %2,%1\n\t"
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- "sbb %0,%0" : "=r" (oldbit), ADDR : "Ir" (nr) : "memory");
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-
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- return oldbit;
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+ GEN_BINARY_RMWcc(LOCK_PREFIX "bts", *addr, nr, "%0", "c");
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}
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/**
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@@ -255,13 +251,7 @@ static inline int __test_and_set_bit(long nr, volatile unsigned long *addr)
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*/
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static inline int test_and_clear_bit(long nr, volatile unsigned long *addr)
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{
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- int oldbit;
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-
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- asm volatile(LOCK_PREFIX "btr %2,%1\n\t"
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- "sbb %0,%0"
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- : "=r" (oldbit), ADDR : "Ir" (nr) : "memory");
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-
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- return oldbit;
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+ GEN_BINARY_RMWcc(LOCK_PREFIX "btr", *addr, nr, "%0", "c");
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}
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/**
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@@ -314,13 +304,7 @@ static inline int __test_and_change_bit(long nr, volatile unsigned long *addr)
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*/
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static inline int test_and_change_bit(long nr, volatile unsigned long *addr)
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{
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- int oldbit;
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-
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- asm volatile(LOCK_PREFIX "btc %2,%1\n\t"
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- "sbb %0,%0"
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- : "=r" (oldbit), ADDR : "Ir" (nr) : "memory");
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-
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- return oldbit;
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+ GEN_BINARY_RMWcc(LOCK_PREFIX "btc", *addr, nr, "%0", "c");
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}
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static __always_inline int constant_test_bit(long nr, const volatile unsigned long *addr)
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diff --git a/arch/x86/include/asm/local.h b/arch/x86/include/asm/local.h
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index 2d89e39..5b23e60 100644
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--- a/arch/x86/include/asm/local.h
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+++ b/arch/x86/include/asm/local.h
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@@ -52,12 +52,7 @@ static inline void local_sub(long i, local_t *l)
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*/
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static inline int local_sub_and_test(long i, local_t *l)
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{
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- unsigned char c;
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-
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- asm volatile(_ASM_SUB "%2,%0; sete %1"
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- : "+m" (l->a.counter), "=qm" (c)
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- : "ir" (i) : "memory");
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- return c;
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+ GEN_BINARY_RMWcc(_ASM_SUB, l->a.counter, i, "%0", "e");
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}
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/**
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@@ -70,12 +65,7 @@ static inline int local_sub_and_test(long i, local_t *l)
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*/
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static inline int local_dec_and_test(local_t *l)
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{
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- unsigned char c;
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-
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- asm volatile(_ASM_DEC "%0; sete %1"
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- : "+m" (l->a.counter), "=qm" (c)
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- : : "memory");
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- return c != 0;
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+ GEN_UNARY_RMWcc(_ASM_DEC, l->a.counter, "%0", "e");
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}
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/**
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@@ -88,12 +78,7 @@ static inline int local_dec_and_test(local_t *l)
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*/
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static inline int local_inc_and_test(local_t *l)
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{
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- unsigned char c;
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-
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- asm volatile(_ASM_INC "%0; sete %1"
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- : "+m" (l->a.counter), "=qm" (c)
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- : : "memory");
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- return c != 0;
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+ GEN_UNARY_RMWcc(_ASM_INC, l->a.counter, "%0", "e");
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}
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/**
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@@ -107,12 +92,7 @@ static inline int local_inc_and_test(local_t *l)
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*/
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static inline int local_add_negative(long i, local_t *l)
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{
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- unsigned char c;
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-
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- asm volatile(_ASM_ADD "%2,%0; sets %1"
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- : "+m" (l->a.counter), "=qm" (c)
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- : "ir" (i) : "memory");
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- return c;
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+ GEN_BINARY_RMWcc(_ASM_ADD, l->a.counter, i, "%0", "s");
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}
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/**
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cgit v0.9.2
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