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Roland Paterson-Jones 18f6f2d5ea Simple Inner Loop Optimzation
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.
2026-05-03 14:37:27 +02:00
amd64 extern DYNCONST 2026-05-03 11:34:53 +02:00
arm64 extern DYNCONST 2026-05-03 11:34:53 +02:00
doc extern DYNCONST 2026-05-03 11:34:53 +02:00
minic minic: C23 doesn't allow bool as identifier 2025-03-16 11:27:49 +01:00
rv64 extern DYNCONST 2026-05-03 11:34:53 +02:00
test formatting fixes in tests 2026-02-12 09:23:13 +01:00
tools extern DYNCONST 2026-05-03 11:34:53 +02:00
.gitignore Global Value Numbering / Global Code Motion 2025-03-14 09:58:37 +01:00
abi.c add new target-specific abi0 pass 2022-10-03 10:41:03 +02:00
alias.c fix bug in alias analysis 2024-03-07 16:40:51 +01:00
all.h Simple Inner Loop Optimzation 2026-05-03 14:37:27 +02:00
cfg.c fix typo in simplcfg 2026-01-13 20:36:23 +01:00
copy.c fix exponential complexity in usewidthle() 2026-04-21 13:25:00 +02:00
emit.c fix float neg on mach-o 2026-04-25 18:51:46 +02:00
fold.c gvn/gcm review 2025-03-14 13:09:21 +01:00
gcm.c gvn/gcm review 2025-03-14 13:09:21 +01:00
gvn.c remove unused variable 2026-02-28 19:05:15 +01:00
ifopt.c If-conversion RFC 4 - x86 only (for now), use cmovXX 2026-01-13 18:11:30 +01:00
LICENSE update copyright years 2026-01-13 17:09:41 +01:00
live.c refine assertion in liveness analysis 2022-06-14 09:11:44 +02:00
load.c gvn/gcm review 2025-03-14 13:09:21 +01:00
loopopt.c Simple Inner Loop Optimzation 2026-05-03 14:37:27 +02:00
main.c Simple Inner Loop Optimzation 2026-05-03 14:37:27 +02:00
Makefile Simple Inner Loop Optimzation 2026-05-03 14:37:27 +02:00
mem.c relax one assert 2024-06-05 12:50:36 +02:00
ops.h ifopt simplifications 2026-01-13 18:11:37 +01:00
parse.c extern DYNCONST 2026-05-03 11:34:53 +02:00
README 10 years of qbe! 2025-03-14 13:09:42 +01:00
rega.c idup(Ins **, Ins *, ulong) -> idup(Blk *, Ins *, ulong) 2025-03-14 09:47:05 +01:00
simpl.c idup(Ins **, Ins *, ulong) -> idup(Blk *, Ins *, ulong) 2025-03-14 09:47:05 +01:00
spill.c fix jmp arg spilling 2026-01-13 17:09:41 +01:00
ssa.c gvn/gcm review 2025-03-14 13:09:21 +01:00
util.c negated conditions rework 2026-04-29 17:45:20 +02:00

QBE - Backend Compiler              http://c9x.me/compile/

doc/    Documentation.
minic/  An example C frontend for QBE.
tools/  Miscellaneous tools (testing).
test/   Tests.
amd64/
arm64/
rv64/   Architecture-specific code.

The LICENSE file applies to all files distributed.

- Compilation and Installation

Invoke make in this directory to create the executable
file qbe.  Install using 'make install', the standard
DESTDIR and PREFIX environment variables are supported.
Alternatively, you may simply copy the qbe binary.