[PATCH] mips: Do not include hi and lo in __SYSCALL_CLOBBERS for R6

[Dragan Mladjenovic]

From: "Dragan Mladjenovic" <dmladjenovic@wavecomp.com>

GCC 10 (PR 91233) won't silently allow registers that are not architecturally
available to be present in the clobber list anymore, resulting in build failure
for mips*r6 targets in form of:
...
.../sysdep.h:146:2: error: the register ‘lo’ cannot be clobbered in ‘asm’ for the current target
  146 |  __asm__ volatile (      \
      |  ^~~~~~~

This is because base R6 ISA doesn't define hi and lo registers w/o DSP extension.
This patch provides the alternative definitions of __SYSCALL_CLOBBERS for r6
targets that won't include those registers.

	* sysdeps/unix/sysv/linux/mips/mips32/sysdep.h (__SYSCALL_CLOBBERS): Exclude
	hi and lo from the clobber list for __mips_isa_rev >= 6.
	* sysdeps/unix/sysv/linux/mips/mips64/n32/sysdep.h (__SYSCALL_CLOBBERS): Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/n64/sysdep.h (__SYSCALL_CLOBBERS): Likewise.
---
 sysdeps/unix/sysv/linux/mips/mips32/sysdep.h     | 9 +++++++--
 sysdeps/unix/sysv/linux/mips/mips64/n32/sysdep.h | 9 +++++++--
 sysdeps/unix/sysv/linux/mips/mips64/n64/sysdep.h | 9 +++++++--
 3 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/sysdeps/unix/sysv/linux/mips/mips32/sysdep.h b/sysdeps/unix/sysv/linux/mips/mips32/sysdep.h
index 86347fe..cbc2a4b 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/sysdep.h
+++ b/sysdeps/unix/sysv/linux/mips/mips32/sysdep.h
@@ -346,8 +346,13 @@ libc_hidden_proto (__mips_syscall7, nomips16)
 	_sc_ret.reg.v0;							\
 })
 
-#define __SYSCALL_CLOBBERS "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13", \
-	"$14", "$15", "$24", "$25", "hi", "lo", "memory"
+#if __mips_isa_rev >= 6
+# define __SYSCALL_CLOBBERS "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13", \
+	 "$14", "$15", "$24", "$25", "memory"
+#else
+# define __SYSCALL_CLOBBERS "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13", \
+	 "$14", "$15", "$24", "$25", "hi", "lo", "memory"
+#endif
 
 #endif /* __ASSEMBLER__ */
 
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n32/sysdep.h b/sysdeps/unix/sysv/linux/mips/mips64/n32/sysdep.h
index ca7a60e..fd16508 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n32/sysdep.h
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n32/sysdep.h
@@ -294,8 +294,13 @@
 	_sys_result;							\
 })
 
-#define __SYSCALL_CLOBBERS "$1", "$3", "$10", "$11", "$12", "$13", \
-	"$14", "$15", "$24", "$25", "hi", "lo", "memory"
+#if __mips_isa_rev >= 6
+# define __SYSCALL_CLOBBERS "$1", "$3", "$10", "$11", "$12", "$13", \
+	 "$14", "$15", "$24", "$25", "memory"
+#else
+# define __SYSCALL_CLOBBERS "$1", "$3", "$10", "$11", "$12", "$13", \
+	 "$14", "$15", "$24", "$25", "hi", "lo", "memory"
+#endif
 
 #endif /* __ASSEMBLER__ */
 
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/sysdep.h b/sysdeps/unix/sysv/linux/mips/mips64/n64/sysdep.h
index 821dec9..8df4d9b 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n64/sysdep.h
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/sysdep.h
@@ -290,8 +290,13 @@
 	_sys_result;							\
 })
 
-#define __SYSCALL_CLOBBERS "$1", "$3", "$10", "$11", "$12", "$13", \
-	"$14", "$15", "$24", "$25", "hi", "lo", "memory"
+#if __mips_isa_rev >= 6
+# define __SYSCALL_CLOBBERS "$1", "$3", "$10", "$11", "$12", "$13", \
+	 "$14", "$15", "$24", "$25", "memory"
+#else
+# define __SYSCALL_CLOBBERS "$1", "$3", "$10", "$11", "$12", "$13", \
+	 "$14", "$15", "$24", "$25", "hi", "lo", "memory"
+#endif
 
 #endif /* __ASSEMBLER__ */
 
-- 
1.9.1