[Bug inline-asm/37758] Assembler failure: Error: syntax error; found `,' but expected `('

["patrick at motec dot com dot au" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #2 from patrick at motec dot com dot au  2008-10-06 23:10 -------
The problem appears to be that the loop

       for (; y < pa; y++) {
          asm(" mullw    16,%3,%4       \n\t"
              " mulhwu   17,%3,%4       \n\t"
              " addc     16,16,%0       \n\t"
              " addze    17,17          \n\t"
              " lwz      18,%1          \n\t"
              " addc     16,16,18       \n\t"
              " addze    %0,17          \n\t"
              " stw      16,%1          \n\t"
             
:"=r"(cy),"=m"(_c[0]):"0"(cy),"r"(mu),"r"(tmpm[0]),"1"(_c[0]):"16", "17",
"18","%cc"); ++tmpm;;
          ++_c;
       }

is being unrolled, resulting in

 # 521 "src/mont/fp_montgomery_reduce.c" 1
         mullw    16,28,0       
         mulhwu   17,28,0       
         addc     16,16,11       
         addze    17,17          
         lwz      18,4(29)          
         addc     16,16,18       
         addze    11,17          
         stw      16,4(29)          

 # 0 "" 2
.L335:
        lwzx 5,31,3
 # 521 "src/mont/fp_montgomery_reduce.c" 1
         mullw    16,28,5       
         mulhwu   17,28,5       
         addc     16,16,11       
         addze    17,17          
         lwz      18,29,3          
         addc     16,16,18       
         addze    11,17          
         stw      16,29,3          

 # 0 "" 2
        addi 3,3,4

and so on...

where the "lwz      18,29,3" is not understood by the assembler.

I am currently working around this problem by making the variable _c volatile,
which prevents the loop from being unrolled.


-- 

patrick at motec dot com dot au changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to fail|                            |4.3.0 4.3.1 4.3.2
      Known to work|                            |4.1.1 4.1.2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37758