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[Qemu-devel] [PATCH 09/15] tcg-sparc: Do not use a global register for A
From: |
Richard Henderson |
Subject: |
[Qemu-devel] [PATCH 09/15] tcg-sparc: Do not use a global register for AREG0. |
Date: |
Sun, 25 Mar 2012 15:27:51 -0700 |
Signed-off-by: Richard Henderson <address@hidden>
---
dyngen-exec.h | 20 +++++++++++---------
exec.c | 16 ++++++++++++++--
2 files changed, 25 insertions(+), 11 deletions(-)
diff --git a/dyngen-exec.h b/dyngen-exec.h
index 65fcb43..d673f9f 100644
--- a/dyngen-exec.h
+++ b/dyngen-exec.h
@@ -41,13 +41,8 @@
#elif defined(__mips__)
#define AREG0 "s0"
#elif defined(__sparc__)
-#ifdef CONFIG_SOLARIS
-#define AREG0 "g2"
-#elif HOST_LONG_BITS == 64
-#define AREG0 "g5"
-#else
-#define AREG0 "g6"
-#endif
+/* Don't use a global register. Working around glibc clobbering these
+ global registers is more trouble than just using TLS. */
#elif defined(__s390__)
#define AREG0 "r10"
#elif defined(__alpha__)
@@ -62,12 +57,19 @@
#error unsupported CPU
#endif
-#if defined(AREG0)
+#ifdef AREG0
register CPUArchState *env asm(AREG0);
#else
-/* TODO: Try env = cpu_single_env. */
+/* It's tempting to #define env cpu_single_cpu, but that runs afoul of
+ the other macro usage in target-foo/helper.h. Instead use an alias.
+ That has to happen where cpu_single_cpu is defined, so just a
+ declaration here. */
+#ifdef __linux__
+extern __thread CPUArchState *env;
+#else
extern CPUArchState *env;
#endif
+#endif /* AREG0 */
#endif /* !CONFIG_TCG_PASS_AREG0 */
#endif /* !defined(__DYNGEN_EXEC_H__) */
diff --git a/exec.c b/exec.c
index 6731ab8..d84caa5 100644
--- a/exec.c
+++ b/exec.c
@@ -124,9 +124,21 @@ static MemoryRegion io_mem_subpage_ram;
#endif
CPUArchState *first_cpu;
-/* current CPU in the current thread. It is only valid inside
- cpu_exec() */
+
+/* Current CPU in the current thread. It is only valid inside cpu_exec(). */
DEFINE_TLS(CPUArchState *,cpu_single_env);
+
+/* In dyngen-exec.h, without AREG0, we fall back to an alias to cpu_single_env.
+ We can't actually tell from here whether that's needed or not, but it does
+ not hurt to go ahead and make the declaration. */
+#ifndef CONFIG_TCG_PASS_AREG0
+extern
+#ifdef __linux__
+ __thread
+#endif
+ CPUArchState *env __attribute__((alias("tls__cpu_single_env")));
+#endif /* CONFIG_TCG_PASS_AREG0 */
+
/* 0 = Do not count executed instructions.
1 = Precise instruction counting.
2 = Adaptive rate instruction counting. */
--
1.7.7.6
- [Qemu-devel] [PATCH 00/15] tcg-sparc improvments, Richard Henderson, 2012/03/25
- [Qemu-devel] [PATCH 01/15] tcg-sparc: Hack in qemu_ld/st64 for 32-bit., Richard Henderson, 2012/03/25
- [Qemu-devel] [PATCH 02/15] tcg-sparc: Fix ADDX opcode., Richard Henderson, 2012/03/25
- [Qemu-devel] [PATCH 06/15] tcg-sparc: Support GUEST_BASE., Richard Henderson, 2012/03/25
- [Qemu-devel] [PATCH 03/15] tcg-sparc: Assume v9 cpu always, i.e. force v8plus in 32-bit mode., Richard Henderson, 2012/03/25
- [Qemu-devel] [PATCH 07/15] tcg-sparc: Steamline qemu_ld/st more., Richard Henderson, 2012/03/25
- [Qemu-devel] [PATCH 09/15] tcg-sparc: Do not use a global register for AREG0.,
Richard Henderson <=
- [Qemu-devel] [PATCH 05/15] tcg-sparc: Simplify qemu_ld/st direct memory paths., Richard Henderson, 2012/03/25
- [Qemu-devel] [PATCH 04/15] tcg-sparc: Fix qemu_ld/st to handle 32-bit host., Richard Henderson, 2012/03/25
- [Qemu-devel] [PATCH 08/15] Avoid declaring the env variable at all if CONFIG_TCG_PASS_AREG0., Richard Henderson, 2012/03/25
- [Qemu-devel] [PATCH 11/15] tcg-sparc: Clean up cruft stemming from attempts to use global registers., Richard Henderson, 2012/03/25
- [Qemu-devel] [PATCH 14/15] tcg-sparc: Add %g/%o registers to alloc_order, Richard Henderson, 2012/03/25