When we split constants with the arm_emit_movpair, we are not setting the REG_EQUAL note. This patch attempts to do that.
Fist patch allow setting REG_EQUAL for ZERO_EXTRACT and handle that in cse (where the src for the ZERO_EXTRACT needs to be calculated) Second patch sets REG_EQUAL when emitting arm_emit_movpair. Bootstrapped and regression tested on arm-none-linux (Chromebook) and x86-64-linux-gnu with no new regression. Is this OK for trunk, Thanks, Kugan
