Before this patch, redundant COPY couldn't be removed for the following case: ``` $R0 = OP ... ... // Read of %R0 $R1 = COPY killed $R0 ``` This patch adds support for tracking the users of the source register during backward propagation, so that we can remove the redundant COPY in the above case and optimize it to: ``` $R1 = OP ... ... // Replace all uses of %R0 with $R1 ```
57 KiB
57 KiB