..., rendering affected code more efficient and smaller.

Note that in atomic.h this at once does away with the redundant output
and input specifications of the memory location touched.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
---
TBD: Do we want to abstract the pattern
	asm ( "...; set<cc> %<out>" : "=<cons>" (var) ... )
matching
	asm ( "..." : "=@cc<cc>" (var) ... )
via some macro? While this would eliminate many (all?) of the
conditionals added here, it would result in the : no longer being
visible in the actual source, making the asm()s look somewhat odd.
Otherwise, to limit code duplication, it may be preferable to put
the #ifdef-s inside the asm()s instead of around them.

--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -610,7 +610,12 @@ do {
  */
 static bool_t even_parity(uint8_t v)
 {
+#ifdef __GCC_ASM_FLAG_OUTPUTS__
+    asm ( "test %1,%1" : "=@ccp" (v) : "q" (v) );
+#else
     asm ( "test %1,%1; setp %0" : "=qm" (v) : "q" (v) );
+#endif
+
     return v;
 }
 
@@ -832,8 +837,14 @@ static int read_ulong(
 static bool_t mul_dbl(unsigned long m[2])
 {
     bool_t rc;
+
+#ifdef __GCC_ASM_FLAG_OUTPUTS__
+    asm ( "mul %1" : "+a" (m[0]), "+d" (m[1]), "=@cco" (rc) );
+#else
     asm ( "mul %1; seto %2"
           : "+a" (m[0]), "+d" (m[1]), "=qm" (rc) );
+#endif
+
     return rc;
 }
 
@@ -845,8 +856,14 @@ static bool_t mul_dbl(unsigned long m[2]
 static bool_t imul_dbl(unsigned long m[2])
 {
     bool_t rc;
+
+#ifdef __GCC_ASM_FLAG_OUTPUTS__
+    asm ( "imul %1" : "+a" (m[0]), "+d" (m[1]), "=@cco" (rc) );
+#else
     asm ( "imul %1; seto %2"
           : "+a" (m[0]), "+d" (m[1]), "=qm" (rc) );
+#endif
+
     return rc;
 }
 
@@ -4651,9 +4668,15 @@ x86_emulate(
     case 0xbc: /* bsf or tzcnt */ {
         bool_t zf;
 
+#ifdef __GCC_ASM_FLAG_OUTPUTS__
+        asm ( "bsf %2,%0"
+              : "=r" (dst.val), "=@ccz" (zf)
+              : "rm" (src.val) );
+#else
         asm ( "bsf %2,%0; setz %1"
               : "=r" (dst.val), "=qm" (zf)
               : "rm" (src.val) );
+#endif
         _regs.eflags &= ~EFLG_ZF;
         if ( (vex.pfx == vex_f3) && vcpu_has_bmi1() )
         {
@@ -4677,9 +4700,15 @@ x86_emulate(
     case 0xbd: /* bsr or lzcnt */ {
         bool_t zf;
 
+#ifdef __GCC_ASM_FLAG_OUTPUTS__
+        asm ( "bsr %2,%0"
+              : "=r" (dst.val), "=@ccz" (zf)
+              : "rm" (src.val) );
+#else
         asm ( "bsr %2,%0; setz %1"
               : "=r" (dst.val), "=qm" (zf)
               : "rm" (src.val) );
+#endif
         _regs.eflags &= ~EFLG_ZF;
         if ( (vex.pfx == vex_f3) && vcpu_has_lzcnt() )
         {
--- a/xen/include/asm-x86/atomic.h
+++ b/xen/include/asm-x86/atomic.h
@@ -193,12 +193,18 @@ static inline void atomic_sub(int i, ato
  */
 static inline int atomic_sub_and_test(int i, atomic_t *v)
 {
-    unsigned char c;
+    bool_t c;
+
+#ifdef __GCC_ASM_FLAG_OUTPUTS__
+    asm volatile ( "lock; subl %2,%0"
+                   : "+m" (*(volatile int *)&v->counter), "=@ccz" (c)
+                   : "ir" (i) : "memory" );
+#else
+    asm volatile ( "lock; subl %2,%0; setz %1"
+                   : "+m" (*(volatile int *)&v->counter), "=qm" (c)
+                   : "ir" (i) : "memory" );
+#endif
 
-    asm volatile (
-        "lock; subl %2,%0; sete %1"
-        : "=m" (*(volatile int *)&v->counter), "=qm" (c)
-        : "ir" (i), "m" (*(volatile int *)&v->counter) : "memory" );
     return c;
 }
 
@@ -240,13 +246,19 @@ static inline void atomic_dec(atomic_t *
  */ 
 static inline int atomic_dec_and_test(atomic_t *v)
 {
-    unsigned char c;
+    bool_t c;
 
-    asm volatile (
-        "lock; decl %0; sete %1"
-        : "=m" (*(volatile int *)&v->counter), "=qm" (c)
-        : "m" (*(volatile int *)&v->counter) : "memory" );
-    return c != 0;
+#ifdef __GCC_ASM_FLAG_OUTPUTS__
+    asm volatile ( "lock; decl %0"
+                   : "+m" (*(volatile int *)&v->counter), "=@ccz" (c)
+                   :: "memory" );
+#else
+    asm volatile ( "lock; decl %0; setz %1"
+                   : "+m" (*(volatile int *)&v->counter), "=qm" (c)
+                   :: "memory" );
+#endif
+
+    return c;
 }
 
 /**
@@ -259,13 +271,19 @@ static inline int atomic_dec_and_test(at
  */ 
 static inline int atomic_inc_and_test(atomic_t *v)
 {
-    unsigned char c;
+    bool_t c;
 
-    asm volatile (
-        "lock; incl %0; sete %1"
-        : "=m" (*(volatile int *)&v->counter), "=qm" (c)
-        : "m" (*(volatile int *)&v->counter) : "memory" );
-    return c != 0;
+#ifdef __GCC_ASM_FLAG_OUTPUTS__
+    asm volatile ( "lock; incl %0"
+                   : "+m" (*(volatile int *)&v->counter), "=@ccz" (c)
+                   :: "memory" );
+#else
+    asm volatile ( "lock; incl %0; setz %1"
+                   : "+m" (*(volatile int *)&v->counter), "=qm" (c)
+                   :: "memory" );
+#endif
+
+    return c;
 }
 
 /**
@@ -279,12 +297,18 @@ static inline int atomic_inc_and_test(at
  */ 
 static inline int atomic_add_negative(int i, atomic_t *v)
 {
-    unsigned char c;
+    bool_t c;
+
+#ifdef __GCC_ASM_FLAG_OUTPUTS__
+    asm volatile ( "lock; addl %2,%0"
+                   : "+m" (*(volatile int *)&v->counter), "=@ccs" (c)
+                   : "ir" (i) : "memory" );
+#else
+    asm volatile ( "lock; addl %2,%0; sets %1"
+                   : "+m" (*(volatile int *)&v->counter), "=qm" (c)
+                   : "ir" (i) : "memory" );
+#endif
 
-    asm volatile (
-        "lock; addl %2,%0; sets %1"
-        : "=m" (*(volatile int *)&v->counter), "=qm" (c)
-        : "ir" (i), "m" (*(volatile int *)&v->counter) : "memory" );
     return c;
 }
 
--- a/xen/include/asm-x86/bitops.h
+++ b/xen/include/asm-x86/bitops.h
@@ -145,8 +145,14 @@ static inline int test_and_set_bit(int n
 {
     int oldbit;
 
+#ifdef __GCC_ASM_FLAG_OUTPUTS__
+    asm volatile ( "lock; btsl %2,%1"
+                   : "=@ccc" (oldbit), "+m" (ADDR) : "Ir" (nr) : "memory" );
+#else
     asm volatile ( "lock; btsl %2,%1\n\tsbbl %0,%0"
-                   : "=r" (oldbit), "+m" (ADDR) : "Ir" (nr) : "memory");
+                   : "=r" (oldbit), "+m" (ADDR) : "Ir" (nr) : "memory" );
+#endif
+
     return oldbit;
 }
 #define test_and_set_bit(nr, addr) ({                   \
@@ -167,10 +173,16 @@ static inline int __test_and_set_bit(int
 {
     int oldbit;
 
-    asm volatile (
-        "btsl %2,%1\n\tsbbl %0,%0"
-        : "=r" (oldbit), "+m" (*(int *)addr)
-        : "Ir" (nr) : "memory" );
+#ifdef __GCC_ASM_FLAG_OUTPUTS__
+    asm volatile ( "btsl %2,%1"
+                   : "=@ccc" (oldbit), "+m" (*(int *)addr)
+                   : "Ir" (nr) : "memory" );
+#else
+    asm volatile ( "btsl %2,%1\n\tsbbl %0,%0"
+                   : "=r" (oldbit), "+m" (*(int *)addr)
+                   : "Ir" (nr) : "memory" );
+#endif
+
     return oldbit;
 }
 #define __test_and_set_bit(nr, addr) ({                 \
@@ -190,8 +202,14 @@ static inline int test_and_clear_bit(int
 {
     int oldbit;
 
+#ifdef __GCC_ASM_FLAG_OUTPUTS__
+    asm volatile ( "lock; btrl %2,%1"
+                   : "=@ccc" (oldbit), "+m" (ADDR) : "Ir" (nr) : "memory" );
+#else
     asm volatile ( "lock; btrl %2,%1\n\tsbbl %0,%0"
-                   : "=r" (oldbit), "+m" (ADDR) : "Ir" (nr) : "memory");
+                   : "=r" (oldbit), "+m" (ADDR) : "Ir" (nr) : "memory" );
+#endif
+
     return oldbit;
 }
 #define test_and_clear_bit(nr, addr) ({                 \
@@ -212,10 +230,16 @@ static inline int __test_and_clear_bit(i
 {
     int oldbit;
 
-    asm volatile (
-        "btrl %2,%1\n\tsbbl %0,%0"
-        : "=r" (oldbit), "+m" (*(int *)addr)
-        : "Ir" (nr) : "memory" );
+#ifdef __GCC_ASM_FLAG_OUTPUTS__
+    asm volatile ( "btrl %2,%1"
+                   : "=@ccc" (oldbit), "+m" (*(int *)addr)
+                   : "Ir" (nr) : "memory" );
+#else
+    asm volatile ( "btrl %2,%1\n\tsbbl %0,%0"
+                   : "=r" (oldbit), "+m" (*(int *)addr)
+                   : "Ir" (nr) : "memory" );
+#endif
+
     return oldbit;
 }
 #define __test_and_clear_bit(nr, addr) ({               \
@@ -228,10 +252,16 @@ static inline int __test_and_change_bit(
 {
     int oldbit;
 
-    asm volatile (
-        "btcl %2,%1\n\tsbbl %0,%0"
-        : "=r" (oldbit), "+m" (*(int *)addr)
-        : "Ir" (nr) : "memory" );
+#ifdef __GCC_ASM_FLAG_OUTPUTS__
+    asm volatile ( "btcl %2,%1"
+                   : "=@ccc" (oldbit), "+m" (*(int *)addr)
+                   : "Ir" (nr) : "memory" );
+#else
+    asm volatile ( "btcl %2,%1\n\tsbbl %0,%0"
+                   : "=r" (oldbit), "+m" (*(int *)addr)
+                   : "Ir" (nr) : "memory" );
+#endif
+
     return oldbit;
 }
 #define __test_and_change_bit(nr, addr) ({              \
@@ -251,8 +281,14 @@ static inline int test_and_change_bit(in
 {
     int oldbit;
 
+#ifdef __GCC_ASM_FLAG_OUTPUTS__
+    asm volatile ( "lock; btcl %2,%1"
+                   : "=@ccc" (oldbit), "+m" (ADDR) : "Ir" (nr) : "memory" );
+#else
     asm volatile ( "lock; btcl %2,%1\n\tsbbl %0,%0"
-                   : "=r" (oldbit), "+m" (ADDR) : "Ir" (nr) : "memory");
+                   : "=r" (oldbit), "+m" (ADDR) : "Ir" (nr) : "memory" );
+#endif
+
     return oldbit;
 }
 #define test_and_change_bit(nr, addr) ({                \
@@ -270,10 +306,16 @@ static inline int variable_test_bit(int
 {
     int oldbit;
 
-    asm volatile (
-        "btl %2,%1\n\tsbbl %0,%0"
-        : "=r" (oldbit)
-        : "m" (CONST_ADDR), "Ir" (nr) : "memory" );
+#ifdef __GCC_ASM_FLAG_OUTPUTS__
+    asm volatile ( "btl %2,%1"
+                   : "=@ccc" (oldbit)
+                   : "m" (CONST_ADDR), "Ir" (nr) : "memory" );
+#else
+    asm volatile ( "btl %2,%1\n\tsbbl %0,%0"
+                   : "=r" (oldbit)
+                   : "m" (CONST_ADDR), "Ir" (nr) : "memory" );
+#endif
+
     return oldbit;
 }
 
--- a/xen/include/asm-x86/hvm/vmx/vmx.h
+++ b/xen/include/asm-x86/hvm/vmx/vmx.h
@@ -406,12 +406,17 @@ static inline bool_t __vmread_safe(unsig
                    VMREAD_OPCODE MODRM_EAX_ECX
 #endif
                    /* CF==1 or ZF==1 --> rc = 0 */
+#ifdef __GCC_ASM_FLAG_OUTPUTS__
+                   : "=@ccnbe" (okay),
+#else
                    "setnbe %0"
+                   : "=qm" (okay),
+#endif
 #ifdef HAVE_GAS_VMX
-                   : "=qm" (okay), "=rm" (*value)
+                     "=rm" (*value)
                    : "r" (field));
 #else
-                   : "=qm" (okay), "=c" (*value)
+                     "=c" (*value)
                    : "a" (field));
 #endif