Re: [PATCH] [rtl/cprop_hardreg] Don't propagate for a more expensive reg-reg move.

[Jeff Law via Gcc-patches]

On 1/24/2022 6:31 PM, liuhongt via Gcc-patches wrote:

For i386, it enables optimization like:

         vmovd   %xmm0, %edx
-       vmovd   %xmm0, %eax
+       movl    %edx, %eax

Bootstrapped and regtested on CLX for both
x86_64-pc-linux-gnu{-m32,} and
x86_64-pc-linux-gnu{-m32\ -march=native,\ -march=native}

Ok for trunk?

gcc/ChangeLog:

        PR rtl-optimization/104059
        * regcprop.cc (copyprop_hardreg_forward_1): Don't propagate
        for a more expensive reg-reg move.

gcc/testsuite/ChangeLog:

        * gcc.target/i386/pr104059.c: New test.

OK
jeff