Check by including memory constaints in your extend pattern.
(define_expand "extendhisi2"
[(set (match_operand:SI 0 "register_operand" "=b,b")
(sign_extend:SI
(match_operand:HI 1 "nonimmediate_operand" " b,m")))] <==
memory operand
""
On Mon, Jan 4, 2010 at 3:09 PM, Prashant Purohit
<prashantpurohit025@xxxxxxxxx> wrote:
>
> Hi,
> I am trying to port gcc-4.3.0 to a custom architecture. The high level
> language selected is C.
> The processor is a RISC processor and all the registers are of 32-bits wide.
> The integer data type (SImode) is set as 32-bits.
>
> I have already completed implementation to support integer data type and it
> works fine. Now I am trying to support other data types such as char
> (8-bits), short int (16-bits).
> I have defined the following things:
> 1. macros in the .h file:
> #define LOAD_EXTEND_OP(MODE) SIGN_EXTEND
>
> #define PROMOTE_MODE(MODE, UNSIGNEDP, TYPE) \
> if (GET_MODE_CLASS (MODE) == MODE_INT \
> && GET_MODE_SIZE (MODE) < 4) \
> { \
> (MODE) = SImode; \
> }
>
> #define PROMOTE_FUNCTION_MODE(MODE, UNSIGNEDP, TYPE) \
> if ((GET_MODE_CLASS (MODE) == MODE_INT \
> || GET_MODE_CLASS (MODE) == MODE_COMPLEX_INT) \
> && GET_MODE_SIZE (MODE) < 4) \
> (MODE) = SImode;
>
> 2. md patterns for zero_extend and extend patterns, movqi and movhi.
>
> The gcc builds successfully and also cc1 compiles the following C code. But
> you can see that the generated assembly has bugs.
>
> C code:
> void main()
> {
> short int c;
> int b;
>
> b = c;
>
> }
>
> generated .s looks something like :
>
> ...function prologue..
> loadHI Reg1, (frame_pointer, #-18)
> storeHI Reg1,[frame_pointer, #-28]
> loadSI Reg2, [frame_pointer, #-28]
> ashiftleft Reg1,Reg2,#16
> ashiftright Reg1,Reg1,#16
> storeSI Reg1,[frame_pointer, #-16]
> ...function epilogue
>
>
> expected .s is:
> ...function prologue..
> loadHI Reg1, (frame_pointer, #-18)
> storeSI Reg1,[frame_pointer, #-16]
> ...function epilogue
>
> I am not able to find out why extra load, store and shift instructions are
> generated.
>
> -Rajeshwari
> --
> View this message in context: http://old.nabble.com/Problem-supporting-char-and-short-int-tp27010666p27010666.html
> Sent from the gcc - Help mailing list archive at Nabble.com.
>
>
