Commit ef5890ebafb7cd2fbf9acf161edb55fe1382871c
2014-03-21T11:01:39
win32.S: Use shifting for multiplication rather than repeated addition The jump table code added a register to itself twice to multiply by 4; shift the register left by 2 instead.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44
diff --git a/src/x86/win32.S b/src/x86/win32.S
index 5ed1221..b455982 100644
--- a/src/x86/win32.S
+++ b/src/x86/win32.S
@@ -568,8 +568,7 @@ USCORE_SYMBOL(ffi_call_win32):
.long .Lretstruct4b-.Lstore_table /* FFI_TYPE_SMALL_STRUCT_4B */
.long .Lretstruct-.Lstore_table /* FFI_TYPE_MS_STRUCT */
1:
- add %ecx, %ecx
- add %ecx, %ecx
+ shl $2, %ecx
add (%esp),%ecx
mov (%ecx),%ecx
add (%esp),%ecx
@@ -727,8 +726,7 @@ USCORE_SYMBOL(ffi_closure_SYSV):
.long .Lcls_retmsstruct-.Lcls_store_table /* FFI_TYPE_MS_STRUCT */
1:
- add %eax, %eax
- add %eax, %eax
+ shl $2, %eax
add (%esp),%eax
mov (%eax),%eax
add (%esp),%eax
@@ -879,8 +877,7 @@ USCORE_SYMBOL(ffi_closure_raw_SYSV):
.long .Lrcls_retstruct4-.Lrcls_store_table /* FFI_TYPE_SMALL_STRUCT_4B */
.long .Lrcls_retstruct-.Lrcls_store_table /* FFI_TYPE_MS_STRUCT */
1:
- add %eax, %eax
- add %eax, %eax
+ shl $2, %eax
add (%esp),%eax
mov (%eax),%eax
add (%esp),%eax
@@ -1005,8 +1002,7 @@ USCORE_SYMBOL(ffi_closure_STDCALL):
.long .Lscls_retstruct2-.Lscls_store_table /* FFI_TYPE_SMALL_STRUCT_2B */
.long .Lscls_retstruct4-.Lscls_store_table /* FFI_TYPE_SMALL_STRUCT_4B */
1:
- add %eax, %eax
- add %eax, %eax
+ shl $2, %eax
add (%esp),%eax
mov (%eax),%eax
add (%esp),%eax