Help in pointing to correct pattern in md file

Help in pointing to correct pattern in md file

[rohitgeek]

I am trying on ARM processor to check on how complex instruction works, but
not getting the expected result.

In arm.md, a pattern for MLA instruction is present which should be used to
emit the instruction " mla  ________ " if i write the test code as : -

main()
  {
  int a,b,c;
  a=10; b=5; c=7;
  a = b*c +b;  //MLA
}

The result is that i get two different instructions. What should in done in
md files or build/compile time to support these kind of instructions.

Thanks
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Re: Help in pointing to correct pattern in md file

[Ian Lance Taylor]

rohitgeek <rohit23taneja@gmail.com> writes:

> In arm.md, a pattern for MLA instruction is present which should be used to
> emit the instruction " mla  ________ " if i write the test code as : -
>
> main()
>   {
>   int a,b,c;
>   a=10; b=5; c=7;
>   a = b*c +b;  //MLA
> }
>
> The result is that i get two different instructions. What should in done in
> md files or build/compile time to support these kind of instructions.

I see the mla instruction if I compile this file:

int foo(int a, int b, int c) { return a * b + c; }

with an ARM compiler with -O2.

Ian