Simple Inner Loop Optimzationloopopt

Two simple loop optimizations.

1. Strength reduction of mul[tiplication] by loop induction
variable.

2. Hoisting of (address) base into phi where loop induction
variable is used only as a base (address) offset.

Limited to loops with a single body block, which happily
is always innermost loops. This restriction would not be
very hard to lift - it would require detecting the set of
loop blocks (and ensuring reducibility?)

Limited to loop induction variables with 0 initial value
and increment of 1 (for mul strength reduction). This
limitation is trivial to lift; however all of the
cproc/hare[c]/coremark opportunity is with 0/1 loops for
mul reduction, and 0 initial value for base-offset opt.

1 files changed, 2 insertions, 1 deletions

diff --git a/Makefile b/Makefile
index 7acaf35..7bcfcec 100644
--- a/Makefile
+++ b/Makefile
@@ -5,7 +5,8 @@ PREFIX = /usr/local
 BINDIR = $(PREFIX)/bin
 
 COMMOBJ  = main.o util.o parse.o abi.o cfg.o mem.o ssa.o alias.o load.o \
-           copy.o fold.o gvn.o gcm.o simpl.o live.o spill.o rega.o emit.o
+           copy.o fold.o gvn.o gcm.o loopopt.o simpl.o live.o spill.o rega.o \
+           emit.o
 AMD64OBJ = amd64/targ.o amd64/sysv.o amd64/isel.o amd64/emit.o
 ARM64OBJ = arm64/targ.o arm64/abi.o arm64/isel.o arm64/emit.o
 RV64OBJ  = rv64/targ.o rv64/abi.o rv64/isel.o rv64/emit.o