On Sun, Nov 08, 2015 at 07:42:04PM -0500, Michael Meissner wrote: > This patch adds support for new fusion forms in ISA 3.0 (power9). In > particular, ISA 3.0 can fuse GPR loads of R0, FPR loads, GPR stores, FPR > stores, and some constant generation that ISA 2.07 (power8) could not > generate.
TOC fusion breaks thousands of testcases with -mlra -flto. What happens is that LRA tries to reload the memory address (the unspec FUSION_ADDIS) into a register, but there is no pattern that will let it do that. This can be fixed temporarily by not enabling TOC fusion if LRA is enabled. It seems that without -flto TOC fusion doesn't do much at all, btw? Segher
