[Guile-commits] 278/437: x86_64: Change x86_64 to also save/restore %rbx in inline asm.

[Andy Wingo]

wingo pushed a commit to branch lightning
in repository guile.

commit c146f067937fbd285ec378b1e7e0583f60a74bae
Author: pcpa <address@hidden>
Date:   Sun Feb 23 17:31:12 2014 -0300

    x86_64: Change x86_64 to also save/restore %rbx in inline asm.
    
        *  lib/jit_x86.c: Rewrite previous patch to inline save/restore
        because clobbering %ebx in x86 is treated as an error
        (jit_x86.c:239:5: error: PIC register clobbered by 'ebx' in 'asm').
---
 ChangeLog     |  6 ++++++
 lib/jit_x86.c | 20 +++++++++++---------
 2 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index f3ab5a0..d5a24a9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2014-23-02 Paulo Andrade <address@hidden>
+
+       *  lib/jit_x86.c: Rewrite previous patch to inline save/restore
+       because clobbering %ebx in x86 is treated as an error
+       (jit_x86.c:239:5: error: PIC register clobbered by 'ebx' in 'asm').
+
 2014-19-02 Paulo Andrade <address@hidden>
 
        * lib/jit_x86.c: Rewrite incorrect inline assembly that could
diff --git a/lib/jit_x86.c b/lib/jit_x86.c
index 027e6db..5eaad68 100644
--- a/lib/jit_x86.c
+++ b/lib/jit_x86.c
@@ -170,7 +170,7 @@ jit_get_cpu(void)
            jit_uint32_t __reserved3    : 1;
            jit_uint32_t __alwayszero   : 1;    /* amd RAZ */
        } bits;
-       jit_uint32_t    cpuid;
+       jit_uword_t     cpuid;
     } ecx;
     union {
        struct {
@@ -207,12 +207,12 @@ jit_get_cpu(void)
            jit_uint32_t __reserved2    : 1;
            jit_uint32_t pbe            : 1;    /* amd reserved */
        } bits;
-       jit_uint32_t    cpuid;
+       jit_uword_t     cpuid;
     } edx;
 #if __WORDSIZE == 32
     int                        ac, flags;
 #endif
-    jit_uint32_t       eax, ebx;
+    jit_uword_t                eax, ebx;
 
 #if __WORDSIZE == 32
     /* adapted from glibc __sysconf */
@@ -236,11 +236,14 @@ jit_get_cpu(void)
 #endif
 
     /* query %eax = 1 function */
-    __asm__ volatile ("cpuid; movl %%ebx, %1"
+#if __WORDSIZE == 32
+    __asm__ volatile ("xchgl %%ebx, %1; cpuid; xchgl %%ebx, %1"
+#else
+    __asm__ volatile ("xchgq %%rbx, %1; cpuid; xchgq %%rbx, %1"
+#endif
                      : "=a" (eax), "=r" (ebx),
                      "=c" (ecx.cpuid), "=d" (edx.cpuid)
-                     : "0" (1)
-                     : "ebx");
+                     : "0" (1));
 
     jit_cpu.fpu                = edx.bits.fpu;
     jit_cpu.cmpxchg8b  = edx.bits.cmpxchg8b;
@@ -262,11 +265,10 @@ jit_get_cpu(void)
 
 #if __WORDSIZE == 64
     /* query %eax = 0x80000001 function */
-    __asm__ volatile ("cpuid; movl %%ebx, %1"
+    __asm__ volatile ("xchgq %%rbx, %1; cpuid; xchgq %%rbx, %1"
                      : "=a" (eax), "=r" (ebx),
                      "=c" (ecx.cpuid), "=d" (edx.cpuid)
-                     : "0" (0x80000001)
-                     : "ebx");
+                     : "0" (0x80000001));
     jit_cpu.lahf       = ecx.cpuid & 1;
 #endif
 }