Fix clobbers so that GENERIC may compile with GCC 2.95.2.

Historically, the documentation of extended asm was lacking, namely you
should NOT specify the same register as an input, and a clobber.
If the register is clobbered, it should be specified as an output as well,
e.g., by linking input and output through the "number" notation.
(Beware of lvalues, some local variables needed...)

URL:http://egcs.cygnus.com/faq.html

In versions up to egcs-1.1.1, the compiler did not even warn about it,
but it was liable to output bad code. Newer egcs are pickier and simply
refuse to swallow such code.

Note, since *addr changes, it needs to be an output operand.
We might be excessive in saying that all memory has changed.

Obtained from:	OpenBSD
		w/extra thanks to Marc Espie <Marc.Espie@liafa.jussieu.fr>

1 files changed, 84 insertions, 83 deletions

diff --git a/sys/i386/include/bus.h b/sys/i386/include/bus.h
index b6a9795..6617612 100644
--- a/sys/i386/include/bus.h
+++ b/sys/i386/include/bus.h
@@ -252,15 +252,14 @@ bus_space_read_multi_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
-		int __x __asm__("%eax");
 		__asm __volatile("				\n\
 			cld					\n\
-		1:	movb (%1),%%al				\n\
+		1:	movb (%2),%%al				\n\
 			stosb					\n\
 			loop 1b"				:
-		    "=&a" (__x)					:
-		    "r" (bsh + offset), "D" (addr), "c" (count)	:
-		    "%edi", "%ecx", "memory");
+		    "=D" (addr), "=c" (count)			:
+		    "r" (bsh + offset), "0" (addr), "1" (count)	:
+		    "%eax", "memory");
 	}
 #endif
 }
@@ -280,15 +279,14 @@ bus_space_read_multi_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
-		int __x __asm__("%eax");
 		__asm __volatile("				\n\
 			cld					\n\
-		1:	movw (%1),%%ax				\n\
+		1:	movw (%2),%%ax				\n\
 			stosw					\n\
 			loop 1b"				:
-		    "=&a" (__x)					:
-		    "r" (bsh + offset), "D" (addr), "c" (count)	:
-		    "%edi", "%ecx", "memory");
+		    "=D" (addr), "=c" (count)			:
+		    "r" (bsh + offset), "0" (addr), "1" (count)	:
+		    "%eax", "memory");
 	}
 #endif
 }
@@ -308,15 +306,14 @@ bus_space_read_multi_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
-		int __x __asm__("%eax");
 		__asm __volatile("				\n\
 			cld					\n\
-		1:	movl (%1),%%eax				\n\
+		1:	movl (%2),%%eax				\n\
 			stosl					\n\
 			loop 1b"				:
-		    "=&a" (__x)					:
-		    "r" (bsh + offset), "D" (addr), "c" (count)	:
-		    "%edi", "%ecx", "memory");
+		    "=D" (addr), "=c" (count)			:
+		    "r" (bsh + offset), "0" (addr), "1" (count)	:
+		    "%eax", "memory");
 	}
 #endif
 }
@@ -355,16 +352,16 @@ bus_space_read_region_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 	if (tag == I386_BUS_SPACE_IO)
 #endif
 	{
-		int __x __asm__("%eax");
+		int _port_ = bsh + offset;			\
 		__asm __volatile("				\n\
 			cld					\n\
-		1:	inb %w1,%%al				\n\
+		1:	inb %w2,%%al				\n\
 			stosb					\n\
-			incl %1					\n\
+			incl %2					\n\
 			loop 1b"				:
-		    "=&a" (__x)					:
-		    "d" (bsh + offset), "D" (addr), "c" (count)	:
-		    "%edx", "%edi", "%ecx", "memory");
+		    "=D" (addr), "=c" (count), "=d" (_port_)	:
+		    "0" (addr), "1" (count), "2" (_port_)	:
+		    "%eax", "memory", "cc");
 	}
 #endif
 #if defined(_I386_BUS_MEMIO_H_)
@@ -372,13 +369,14 @@ bus_space_read_region_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
+		int _port_ = bsh + offset;			\
 		__asm __volatile("				\n\
 			cld					\n\
 			repne					\n\
 			movsb"					:
-								:
-		    "S" (bsh + offset), "D" (addr), "c" (count)	:
-		    "%esi", "%edi", "%ecx", "memory");
+		    "=D" (addr), "=c" (count), "=S" (_port_)	:
+		    "0" (addr), "1" (count), "2" (_port_)	:
+		    "memory", "cc");
 	}
 #endif
 }
@@ -392,16 +390,16 @@ bus_space_read_region_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 	if (tag == I386_BUS_SPACE_IO)
 #endif
 	{
-		int __x __asm__("%eax");
+		int _port_ = bsh + offset;			\
 		__asm __volatile("				\n\
 			cld					\n\
-		1:	inw %w1,%%ax				\n\
+		1:	inw %w2,%%ax				\n\
 			stosw					\n\
-			addl $2,%1				\n\
+			addl $2,%2				\n\
 			loop 1b"				:
-		    "=&a" (__x)					:
-		    "d" (bsh + offset), "D" (addr), "c" (count)	:
-		    "%edx", "%edi", "%ecx", "memory");
+		    "=D" (addr), "=c" (count), "=d" (_port_)	:
+		    "0" (addr), "1" (count), "2" (_port_)	:
+		    "%eax", "memory", "cc");
 	}
 #endif
 #if defined(_I386_BUS_MEMIO_H_)
@@ -409,13 +407,14 @@ bus_space_read_region_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
+		int _port_ = bsh + offset;			\
 		__asm __volatile("				\n\
 			cld					\n\
 			repne					\n\
 			movsw"					:
-								:
-		    "S" (bsh + offset), "D" (addr), "c" (count)	:
-		    "%esi", "%edi", "%ecx", "memory");
+		    "=D" (addr), "=c" (count), "=S" (_port_)	:
+		    "0" (addr), "1" (count), "2" (_port_)	:
+		    "memory", "cc");
 	}
 #endif
 }
@@ -429,16 +428,16 @@ bus_space_read_region_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 	if (tag == I386_BUS_SPACE_IO)
 #endif
 	{
-		int __x __asm__("%eax");
+		int _port_ = bsh + offset;			\
 		__asm __volatile("				\n\
 			cld					\n\
-		1:	inl %w1,%%eax				\n\
+		1:	inl %w2,%%eax				\n\
 			stosl					\n\
-			addl $4,%1				\n\
+			addl $4,%2				\n\
 			loop 1b"				:
-		    "=&a" (__x)					:
-		    "d" (bsh + offset), "D" (addr), "c" (count)	:
-		    "%edx", "%edi", "%ecx", "memory");
+		    "=D" (addr), "=c" (count), "=d" (_port_)	:
+		    "0" (addr), "1" (count), "2" (_port_)	:
+		    "%eax", "memory", "cc");
 	}
 #endif
 #if defined(_I386_BUS_MEMIO_H_)
@@ -446,13 +445,14 @@ bus_space_read_region_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
+		int _port_ = bsh + offset;			\
 		__asm __volatile("				\n\
 			cld					\n\
 			repne					\n\
 			movsl"					:
-								:
-		    "S" (bsh + offset), "D" (addr), "c" (count)	:
-		    "%esi", "%edi", "%ecx", "memory");
+		    "=D" (addr), "=c" (count), "=S" (_port_)	:
+		    "0" (addr), "1" (count), "2" (_port_)	:
+		    "memory", "cc");
 	}
 #endif
 }
@@ -573,15 +573,14 @@ bus_space_write_multi_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
-		int __x __asm__("%eax");
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	lodsb					\n\
-			movb %%al,(%1)				\n\
+			movb %%al,(%2)				\n\
 			loop 1b"				:
-		    "=&a" (__x)					:
-		    "r" (bsh + offset), "S" (addr), "c" (count)	:
-		    "%esi", "%ecx");
+		    "=S" (addr), "=c" (count)			:
+		    "r" (bsh + offset), "0" (addr), "1" (count)	:
+		    "%eax", "memory", "cc");
 	}
 #endif
 }
@@ -601,15 +600,15 @@ bus_space_write_multi_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
-		int __x __asm__("%eax");
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	lodsw					\n\
 			movw %%ax,(%1)				\n\
+			movw %%ax,(%2)				\n\
 			loop 1b"				:
-		    "=&a" (__x)					:
-		    "r" (bsh + offset), "S" (addr), "c" (count)	:
-		    "%esi", "%ecx");
+		    "=S" (addr), "=c" (count)			:
+		    "r" (bsh + offset), "0" (addr), "1" (count)	:
+		    "%eax", "memory", "cc");
 	}
 #endif
 }
@@ -629,15 +628,14 @@ bus_space_write_multi_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
-		int __x __asm__("%eax");
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	lodsl					\n\
-			movl %%eax,(%1)				\n\
+			movl %%eax,(%2)				\n\
 			loop 1b"				:
-		    "=&a" (__x)					:
-		    "r" (bsh + offset), "S" (addr), "c" (count)	:
-		    "%esi", "%ecx");
+		    "=S" (addr), "=c" (count)			:
+		    "r" (bsh + offset), "0" (addr), "1" (count)	:
+		    "%eax", "memory", "cc");
 	}
 #endif
 }
@@ -677,16 +675,16 @@ bus_space_write_region_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 	if (tag == I386_BUS_SPACE_IO)
 #endif
 	{
-		int __x __asm__("%eax");
+		int _port_ = bsh + offset;			\
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	lodsb					\n\
-			outb %%al,%w1				\n\
-			incl %1					\n\
+			outb %%al,%w0				\n\
+			incl %0					\n\
 			loop 1b"				:
-		    "=&a" (__x)					:
-		    "d" (bsh + offset), "S" (addr), "c" (count)	:
-		    "%edx", "%esi", "%ecx", "memory");
+		    "=d" (_port_), "=S" (addr), "=c" (count)	:
+		    "0" (_port_), "1" (addr), "2" (count)	:
+		    "%eax", "memory", "cc");
 	}
 #endif
 #if defined(_I386_BUS_MEMIO_H_)
@@ -694,13 +692,14 @@ bus_space_write_region_1(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
+		int _port_ = bsh + offset;			\
 		__asm __volatile("				\n\
 			cld					\n\
 			repne					\n\
 			movsb"					:
-								:
-		    "D" (bsh + offset), "S" (addr), "c" (count)	:
-		    "%edi", "%esi", "%ecx", "memory");
+		    "=D" (_port_), "=S" (addr), "=c" (count)	:
+		    "0" (_port_), "1" (addr), "2" (count)	:
+		    "memory", "cc");
 	}
 #endif
 }
@@ -714,16 +713,16 @@ bus_space_write_region_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 	if (tag == I386_BUS_SPACE_IO)
 #endif
 	{
-		int __x __asm__("%eax");
+		int _port_ = bsh + offset;			\
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	lodsw					\n\
-			outw %%ax,%w1				\n\
-			addl $2,%1				\n\
+			outw %%ax,%w0				\n\
+			addl $2,%0				\n\
 			loop 1b"				:
-		    "=&a" (__x)					:
-		    "d" (bsh + offset), "S" (addr), "c" (count)	:
-		    "%edx", "%esi", "%ecx", "memory");
+		    "=d" (_port_), "=S" (addr), "=c" (count)	:
+		    "0" (_port_), "1" (addr), "2" (count)	:
+		    "%eax", "memory", "cc");
 	}
 #endif
 #if defined(_I386_BUS_MEMIO_H_)
@@ -731,13 +730,14 @@ bus_space_write_region_2(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
+		int _port_ = bsh + offset;			\
 		__asm __volatile("				\n\
 			cld					\n\
 			repne					\n\
 			movsw"					:
-								:
-		    "D" (bsh + offset), "S" (addr), "c" (count)	:
-		    "%edi", "%esi", "%ecx", "memory");
+		    "=D" (_port_), "=S" (addr), "=c" (count)	:
+		    "0" (_port_), "1" (addr), "2" (count)	:
+		    "memory", "cc");
 	}
 #endif
 }
@@ -751,16 +751,16 @@ bus_space_write_region_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 	if (tag == I386_BUS_SPACE_IO)
 #endif
 	{
-		int __x __asm__("%eax");
+		int _port_ = bsh + offset;			\
 		__asm __volatile("				\n\
 			cld					\n\
 		1:	lodsl					\n\
-			outl %%eax,%w1				\n\
-			addl $4,%1				\n\
+			outl %%eax,%w0				\n\
+			addl $4,%0				\n\
 			loop 1b"				:
-		    "=&a" (__x)					:
-		    "d" (bsh + offset), "S" (addr), "c" (count)	:
-		    "%edx", "%esi", "%ecx", "memory");
+		    "=d" (_port_), "=S" (addr), "=c" (count)	:
+		    "0" (_port_), "1" (addr), "2" (count)	:
+		    "%eax", "memory", "cc");
 	}
 #endif
 #if defined(_I386_BUS_MEMIO_H_)
@@ -768,13 +768,14 @@ bus_space_write_region_4(bus_space_tag_t tag, bus_space_handle_t bsh,
 	else
 #endif
 	{
+		int _port_ = bsh + offset;			\
 		__asm __volatile("				\n\
 			cld					\n\
 			repne					\n\
 			movsl"					:
-								:
-		    "D" (bsh + offset), "S" (addr), "c" (count)	:
-		    "%edi", "%esi", "%ecx", "memory");
+		    "=D" (_port_), "=S" (addr), "=c" (count)	:
+		    "0" (_port_), "1" (addr), "2" (count)	:
+		    "memory", "cc");
 	}
 #endif
 }