Change callee-save regs for x64 interpreter to shorten code.

2 files changed, 9 insertions, 2 deletions

diff --git a/src/buildvm_x86.dasc b/src/buildvm_x86.dasc
index fa9bf9fb..84bfd50c 100644
--- a/src/buildvm_x86.dasc
+++ b/src/buildvm_x86.dasc
@@ -23,16 +23,18 @@
 |.define KBASE,         edi             // Must be C callee-save.
 |.define KBASEa,        KBASE
 |.define PC,            esi             // Must be C callee-save.
+|.define DISPATCH,      ebx             // Must be C callee-save.
 |.elif X64WIN
 |.define KBASE,         edi             // Must be C callee-save.
 |.define KBASEa,        rdi
 |.define PC,            esi             // Must be C callee-save.
+|.define DISPATCH,      ebx             // Must be C callee-save.
 |.else
 |.define KBASE,         r15d            // Must be C callee-save.
 |.define KBASEa,        r15
-|.define PC,            r14d            // Must be C callee-save.
+|.define PC,            ebx             // Must be C callee-save.
+|.define DISPATCH,      r14d            // Must be C callee-save.
 |.endif
-|.define DISPATCH,      ebx             // Must be C callee-save.
 |
 |.define RA,            ecx
 |.if X64; .define RAa, rcx; .else; .define RAa, RA; .endif
diff --git a/src/lj_target_x86.h b/src/lj_target_x86.h
index 2fb3c4b8..198245cd 100644
--- a/src/lj_target_x86.h
+++ b/src/lj_target_x86.h
@@ -40,8 +40,13 @@ enum {
 
   /* These definitions must match with the *.dasc file(s): */
   RID_BASE = RID_EDX,           /* Interpreter BASE. */
+#if LJ_64 && !defined(_WIN64)
+  RID_PC = RID_EBX,             /* Interpreter PC. */
+  RID_DISPATCH = RID_R14D,      /* Interpreter DISPATCH table. */
+#else
   RID_PC = RID_ESI,             /* Interpreter PC. */
   RID_DISPATCH = RID_EBX,       /* Interpreter DISPATCH table. */
+#endif
 
   /* Register ranges [min, max) and number of registers. */
   RID_MIN_GPR = RID_EAX,