On 2/20/07, Revital1 Eres <[EMAIL PROTECTED]> wrote:
Hello,
We saw that the reassociation pass does not operate on built-in functions,
for example:
vp3 = vec_madd (vp1, vp2, vp3);
In the RTL level the function is expanded to regular insn:
(insn 87 91 88 9 (set (reg/v:V4SF 217 [ vp3 ])
(plus:V4SF (mult:V4SF (reg/v:V4SF 219 [ vp1 ])
(reg/v:V4SF 218 [ vp2 ]))
(reg/v:V4SF 217 [ vp3 ]))) -1 (nil)
(nil))
The reassociation could open opportunity for the variable expansion
optimization to be applied when vec_madd is in a loop.
(this is what the reassociation pass do for similar accumulation
instruction that is not in built-in function)
Currently MVE fails as it expects the pattern:
x = x + something
while it finds:
x = something + x
I could fix this in the MVE code, but I was wondering about the
relations of reassociation pass and built-in functions in general.
If you find builtin functions you want to reassociate, this is
generally a good sign they should have been expanded to trees rather
than kept as builtins.
If you expanded them, they would have been reassociated (or at least,
they should be. I think we reassociate vector calculations, but it's
been a while since i looked).
