NVPTX/dont-introduce-addrspacecast.ll required manually removing a check for
a bitcast.
AArch64/combine-address-mode.ll required rerunning update_test_checks
Mips required some manual updates due to a CHECK-NEXT coming after a
deleted bitcast.
ARM/sink-addrmode.ll needed one small manual fix.
Excludes one X86 function which needs more attention.
On some targets, like SPARC, forming overflow ops is only profitable if
the math result is used: https://godbolt.org/z/DxSmdB
This patch adds a new MathUsed parameter to allow the targets
to make the decision and defaults to only allowing it
if the math result is used. That is the conservative choice.
This patch also updates AArch64ISelLowering, X86ISelLowering,
ARMISelLowering.h, SystemZISelLowering.h to allow forming overflow
ops if the math result is not used. On those targets using the
overflow intrinsic for the overflow check only generates better code.
Reviewers: nikic, RKSimon, lebedev.ri, spatel
Reviewed By: lebedev.ri
Differential Revision: https://reviews.llvm.org/D74722
