implement Transforms/LoopStrengthReduce/dont-hoist-simple-loop-constants.ll.
We used to emit this code for it:
_test:
li r2, 1 ;; Value tying up a register for the whole loop
li r5, 0
LBB_test_1: ; no_exit.2
or r6, r5, r5
li r5, 0
stw r5, 0(r3)
addi r5, r6, 1
addi r3, r3, 4
add r7, r2, r5 ;; should be addi r7, r5, 1
cmpwi cr0, r7, 701
blt cr0, LBB_test_1 ; no_exit.2
LBB_test_2: ; loopexit.2.loopexit
addi r2, r6, 2
stw r2, 0(r4)
blr
now we emit this:
_test:
li r2, 0
LBB_test_1: ; no_exit.2
or r5, r2, r2
li r2, 0
stw r2, 0(r3)
addi r3, r3, 4
addi r2, r5, 1
addi r6, r5, 2 ;; whoa, fold those adds!
cmpwi cr0, r6, 701
blt cr0, LBB_test_1 ; no_exit.2
LBB_test_2: ; loopexit.2.loopexit
addi r2, r5, 2
stw r2, 0(r4)
blr
more improvement coming.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23306 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed