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Re: [PATCH] Fix PR32843, testsuite bug wrt sign/zero-extension of return values
This fixes the real bug, which is that x86 libffi wasn't correctly
sign/zero extending retvals. I also changed the long chain of
if/then/elses into a switch and tidied things a bit.
While I was doing this, I found a bug in ffi_call_SYSV: in some cases
we were popping too many values from the stack, but that was being
concealed by a later movl %ebp,%esp in the epilogue. As it turns out,
there isn't any need to pop the args from the stack after calling the
user's target function, so I just removed the code that did that.
Passes full testsuite on 32/64, no regressions.
Andrew.
2007-07-30 Andrew Haley <aph@redhat.com>
PR testsuite/32843
* src/x86/ffi.c (ffi_prep_cif_machdep): in x86 case, add code for
signed/unsigned int8/16.
* src/x86/sysv.S (ffi_call_SYSV): Rewrite to:
Use a jump table.
Remove code to pop args from the stack after call.
Special-case signed/unsigned int8/16.
* testsuite/libffi.call/return_sc.c (main): Revert.
Index: src/x86/ffi.c
===================================================================
--- src/x86/ffi.c (revision 127059)
+++ src/x86/ffi.c (working copy)
@@ -121,7 +121,12 @@
case FFI_TYPE_VOID:
#ifdef X86
case FFI_TYPE_STRUCT:
+ case FFI_TYPE_UINT8:
+ case FFI_TYPE_UINT16:
+ case FFI_TYPE_SINT8:
+ case FFI_TYPE_SINT16:
#endif
+
case FFI_TYPE_SINT64:
case FFI_TYPE_FLOAT:
case FFI_TYPE_DOUBLE:
Index: src/x86/sysv.S
===================================================================
--- src/x86/sysv.S (revision 127059)
+++ src/x86/sysv.S (working copy)
@@ -59,16 +59,15 @@
call *28(%ebp)
- /* Remove the space we pushed for the args */
- movl 16(%ebp),%ecx
- addl %ecx,%esp
-
/* Load %ecx with the return type code */
movl 20(%ebp),%ecx
+ /* Protect %esi. We're going to pop it in the epilogue. */
+ pushl %esi
+
/* If the return value pointer is NULL, assume no return value. */
cmpl $0,24(%ebp)
- jne retint
+ jne 0f
/* Even if there is no space for the return value, we are
obliged to handle floating-point values. */
@@ -78,51 +77,84 @@
jmp epilogue
-retint:
- cmpl $FFI_TYPE_INT,%ecx
- jne retfloat
- /* Load %ecx with the pointer to storage for the return value */
- movl 24(%ebp),%ecx
- movl %eax,0(%ecx)
- jmp epilogue
+0:
+ call 1f
+
+.Lstore_table:
+ .long noretval-.Lstore_table /* FFI_TYPE_VOID */
+ .long retint-.Lstore_table /* FFI_TYPE_INT */
+ .long retfloat-.Lstore_table /* FFI_TYPE_FLOAT */
+ .long retdouble-.Lstore_table /* FFI_TYPE_DOUBLE */
+ .long retlongdouble-.Lstore_table /* FFI_TYPE_LONGDOUBLE */
+ .long retuint8-.Lstore_table /* FFI_TYPE_UINT8 */
+ .long retsint8-.Lstore_table /* FFI_TYPE_SINT8 */
+ .long retuint16-.Lstore_table /* FFI_TYPE_UINT16 */
+ .long retsint16-.Lstore_table /* FFI_TYPE_SINT16 */
+ .long retint-.Lstore_table /* FFI_TYPE_UINT32 */
+ .long retint-.Lstore_table /* FFI_TYPE_SINT32 */
+ .long retint64-.Lstore_table /* FFI_TYPE_UINT64 */
+ .long retint64-.Lstore_table /* FFI_TYPE_SINT64 */
+ .long retstruct-.Lstore_table /* FFI_TYPE_STRUCT */
+ .long retint-.Lstore_table /* FFI_TYPE_POINTER */
+
+1:
+ pop %esi
+ add (%esi, %ecx, 4), %esi
+ jmp *%esi
+
+ /* Sign/zero extend as appropriate. */
+retsint8:
+ movsbl %al, %eax
+ jmp retint
+
+retsint16:
+ movswl %ax, %eax
+ jmp retint
+
+retuint8:
+ movzbl %al, %eax
+ jmp retint
+
+retuint16:
+ movzwl %ax, %eax
+ jmp retint
retfloat:
- cmpl $FFI_TYPE_FLOAT,%ecx
- jne retdouble
/* Load %ecx with the pointer to storage for the return value */
movl 24(%ebp),%ecx
fstps (%ecx)
jmp epilogue
retdouble:
- cmpl $FFI_TYPE_DOUBLE,%ecx
- jne retlongdouble
/* Load %ecx with the pointer to storage for the return value */
movl 24(%ebp),%ecx
fstpl (%ecx)
jmp epilogue
retlongdouble:
- cmpl $FFI_TYPE_LONGDOUBLE,%ecx
- jne retint64
/* Load %ecx with the pointer to storage for the return value */
movl 24(%ebp),%ecx
fstpt (%ecx)
jmp epilogue
retint64:
- cmpl $FFI_TYPE_SINT64,%ecx
- jne retstruct
/* Load %ecx with the pointer to storage for the return value */
movl 24(%ebp),%ecx
movl %eax,0(%ecx)
movl %edx,4(%ecx)
+ jmp epilogue
+retint:
+ /* Load %ecx with the pointer to storage for the return value */
+ movl 24(%ebp),%ecx
+ movl %eax,0(%ecx)
+
retstruct:
/* Nothing to do! */
noretval:
epilogue:
+ popl %esi
movl %ebp,%esp
popl %ebp
ret
@@ -162,7 +194,15 @@
movl -12(%ebp), %ecx
cmpl $FFI_TYPE_INT, %eax
je .Lcls_retint
- cmpl $FFI_TYPE_FLOAT, %eax
+
+ /* Handle FFI_TYPE_UINT8, FFI_TYPE_SINT8, FFI_TYPE_UINT16,
+ FFI_TYPE_SINT16, FFI_TYPE_UINT32, FFI_TYPE_SINT32. */
+ cmpl $FFI_TYPE_UINT64, %eax
+ jge 0f
+ cmpl $FFI_TYPE_UINT8, %eax
+ jge .Lcls_retint
+
+0: cmpl $FFI_TYPE_FLOAT, %eax
je .Lcls_retfloat
cmpl $FFI_TYPE_DOUBLE, %eax
je .Lcls_retdouble
Index: testsuite/libffi.call/return_sc.c
===================================================================
--- testsuite/libffi.call/return_sc.c (revision 127059)
+++ testsuite/libffi.call/return_sc.c (working copy)
@@ -30,7 +30,7 @@
sc < (signed char) 127; sc++)
{
ffi_call(&cif, FFI_FN(return_sc), &rint, values);
- CHECK((signed char) rint == sc);
+ CHECK(rint == (ffi_arg) sc);
}
exit(0);
}