compiler: optimization improvements

* stdlib/optimize.tl (basic-blocks peephole-block): Drop the
code argument, and operate on bl.insns, which is stored
back.  Perform the renames in the rename list after the
peephole pass.
(basic-blocks rename): New method.
(basic-blocks do-peephole-block): Implementation of
peephole-block, under a new name.  The local function called
rename is removed; calls to it go to the new rename method.
(basic-blocks peephole): Simplify code around calls to
peephole-block; we no longer have to pass bl.insns to it,
capture the return value and store it back into bl.insns.

* stdlib/compiler.tl (*opt-level*): Initial
value changes from 6 to 7.
(compiler optimize): At optimization level 6,
we now do another jump threading pass, and
peephole, like at levels 4 and 5. The peephole
optimizations at level 5 make it possible
to coalesce some basic blocks in some cases,
and that opens up the possibility for more
reductions. The previously level 6 optimizations
are moved to level 7.

* txr.1: Updated documentation of optimization levels,
and default value of *opt-level*.

* stdlib/doc-syms.tl: Updated.

3 files changed, 85 insertions, 73 deletions

diff --git a/stdlib/compiler.tl b/stdlib/compiler.tl
index 5e5fff6b..2a8f97cd 100644
--- a/stdlib/compiler.tl
+++ b/stdlib/compiler.tl
@@ -378,8 +378,9 @@
 ;; 3 - lambda/combinator lifting
 ;; 4 - control-flow: jump-threading, dead code
 ;; 5 - data-flow: dead registers, useless regisers
-;; 6 - more expensive size or speed optimizations
-(defvar usr:*opt-level* 6)
+;; 6 - iterate on 4-5 optimizations.
+;; 7 - more expensive size or speed optimizations
+(defvar usr:*opt-level* 7)
 
 (defun dedup (obj)
   (cond
@@ -1724,9 +1725,15 @@
         (when (>= olev 5)
           bb.(calc-liveness)
           bb.(peephole)
-          bb.(elim-dead-code))
+          (when (>= olev 6)
+             bb.(link-graph)
+             bb.(thread-jumps))
+          bb.(elim-dead-code)
+          (when (>= olev 6)
+            bb.(calc-liveness)
+            bb.(peephole)))
         (cond
-          ((>= olev 6)
+          ((>= olev 7)
            bb.(merge-jump-thunks)
            bb.(compact-tregs)
            bb.(late-peephole bb.(get-insns)))
diff --git a/stdlib/doc-syms.tl b/stdlib/doc-syms.tl
index 36df7eea..57ccce7f 100644
--- a/stdlib/doc-syms.tl
+++ b/stdlib/doc-syms.tl
@@ -4,7 +4,7 @@
       ("%e%" "N-03F0FA9E")
       ("%fun%" "N-00719365")
       ("%pi%" "N-03F0FA9E")
-      ("*" "D-003A")
+      ("*" "D-0039")
       ("*args*" "N-03DEE18A")
       ("*args-eff*" "N-03DEE18A")
       ("*args-full*" "N-03DEE18A")
@@ -54,7 +54,7 @@
       ("*tree-fun-whitelist*" "N-025AB9C9")
       ("*unhandled-hook*" "N-02B4A4FB")
       ("+" "D-0045")
-      ("-" "D-004B")
+      ("-" "D-004A")
       ("--" "N-0234C408")
       ("--rng" "N-01A056E4")
       ("--rng+" "N-01A056E4")
@@ -64,7 +64,7 @@
       ("-rng" "N-01A056E4")
       ("-rng+" "N-01A056E4")
       ("-rng-" "N-01A056E4")
-      ("/" "D-004A")
+      ("/" "D-004B")
       ("//" "N-0054C409")
       ("/=" "N-003BE40C")
       (":delegate" "N-037F664C")
@@ -74,18 +74,18 @@
       ("<" "D-0058")
       ("<!" "N-02B10DF9")
       ("<-" "N-02B10DF9")
-      ("<=" "D-001E")
-      ("=" "D-007A")
-      (">" "D-0062")
-      (">=" "D-0054")
+      ("<=" "D-0020")
+      ("=" "D-0079")
+      (">" "D-0063")
+      (">=" "D-0052")
       ("abort" "N-02F934F6")
       ("abs" "D-0017")
       ("abs-path-p" "N-00477B23")
-      ("accept" "D-0044")
+      ("accept" "D-0043")
       ("acons" "N-02E9343D")
       ("acons-new" "N-0371BAFA")
       ("aconsql-new" "N-01E315BD")
-      ("acos" "D-0028")
+      ("acos" "D-0026")
       ("acosh" "D-0042")
       ("add" "N-03244398")
       ("add*" "N-03244398")
@@ -130,8 +130,8 @@
       ("arraysize" "N-002129D6")
       ("as" "N-028B26DD")
       ("ash" "D-0065")
-      ("asin" "D-003D")
-      ("asinh" "D-0004")
+      ("asin" "D-003F")
+      ("asinh" "D-0001")
       ("assert" "D-0061")
       ("assoc" "N-00E9306D")
       ("assq" "N-00123702")
@@ -139,7 +139,7 @@
       ("at-exit-call" "N-003EEEF5")
       ("at-exit-do-not-call" "N-003EEEF5")
       ("atan" "D-0051")
-      ("atan2" "D-000A")
+      ("atan2" "D-0009")
       ("atanh" "D-0024")
       ("atom" "N-0076C7BE")
       ("awk" "D-0059")
@@ -157,13 +157,13 @@
       ("bchar" "N-0008D7DC")
       ("bignum-len" "N-020294AB")
       ("bignump" "N-03E9D6E1")
-      ("bind" "D-006F")
+      ("bind" "D-006D")
       ("bindable" "N-0222F2E3")
       ("bit" "D-004D")
-      ("bitset" "D-0037")
+      ("bitset" "D-0038")
       ("blkcnt-t" "N-01153D9E")
       ("blksize-t" "N-01153D9E")
-      ("block" "D-0071")
+      ("block" "D-006F")
       ("block*" "N-02F60DCE")
       ("bool" "D-002C")
       ("boundp" "N-01FBF828")
@@ -281,7 +281,7 @@
       ("cat-str" "N-00B6ACE3")
       ("cat-streams" "N-020BF082")
       ("cat-vec" "N-01AEB28B")
-      ("catch" "D-0011")
+      ("catch" "D-000F")
       ("catch*" "N-0211F3D3")
       ("catch**" "N-0211F3D3")
       ("catch-frame" "N-0233BAE3")
@@ -292,7 +292,7 @@
       ("cdar" "N-001FA3CB")
       ("cdddddr" "N-001FA3CB")
       ("cddr" "N-001FA3CB")
-      ("cdr" "D-0079")
+      ("cdr" "D-007A")
       ("ceil" "D-007E")
       ("ceil-rem" "N-02DE978F")
       ("ceil1" "N-02C8FF28")
@@ -341,7 +341,7 @@
       ("clocal" "N-01B1B5DF")
       ("clock-t" "N-01B6F219")
       ("clockid-t" "N-01153D9E")
-      ("close" "D-0016")
+      ("close" "D-0015")
       ("close-lazy-streams" "N-00B8ACD5")
       ("close-stream" "N-00596930")
       ("closedir" "N-01FEE88A")
@@ -350,7 +350,7 @@
       ("cmp-str" "N-0143A273")
       ("cmspar" "N-01B1B5DF")
       ("coded-length" "N-0167F423")
-      ("coll" "D-005A")
+      ("coll" "D-005B")
       ("collect" "D-0030")
       ("collect-each" "N-0105F01D")
       ("collect-each*" "N-0105F01D")
@@ -453,7 +453,7 @@
       ("data" "N-03B6EA7D")
       ("dec" "N-03A0AABD")
       ("defer-warning" "N-001106AB")
-      ("defex" "D-005E")
+      ("defex" "D-005F")
       ("deffi" "N-00DCE51D")
       ("deffi-cb" "N-00C54FC8")
       ("deffi-cb-unsafe" "N-00C54FC8")
@@ -528,7 +528,7 @@
       ("dump-deferred-warnings" "N-0335651E")
       ("dup" "N-0387F549")
       ("dupfd" "N-01F91AEF")
-      ("dwim" "D-001F")
+      ("dwim" "D-001E")
       ("e2big" "N-036B1BDB")
       ("eacces" "N-036B1BDB")
       ("each" "N-0105F01D")
@@ -658,7 +658,7 @@
       ("etypecase" "N-033FBE77")
       ("eval" "N-0286C8B8")
       ("eval-only" "N-030BF4F5")
-      ("evenp" "D-001C")
+      ("evenp" "D-0019")
       ("ewouldblock" "N-036B1BDB")
       ("exception-subtype-map" "N-03ABFA6D")
       ("exception-subtype-p" "N-02E7F869")
@@ -672,7 +672,7 @@
       ("expand-left" "N-00E168FE")
       ("expand-right" "N-023B6B64")
       ("expand-with-free-refs" "N-0334827B")
-      ("expt" "D-0077")
+      ("expt" "D-0076")
       ("exptmod" "D-0036")
       ("extproc" "N-0072FF5E")
       ("f" "N-003BDFA9")
@@ -737,7 +737,7 @@
       ("file-put-lines" "N-0041C2E5")
       ("file-put-string" "N-0041C2E5")
       ("fileno" "N-008ACF75")
-      ("fill-buf" "D-0026")
+      ("fill-buf" "D-0028")
       ("fill-buf-adjust" "N-00D142E1")
       ("fill-carray" "N-00737951")
       ("fill-obj" "N-0039A1D1")
@@ -862,10 +862,10 @@
       ("gequal" "N-00A3E42D")
       ("get" "N-03D9F55D")
       ("get-buf-from-stream" "N-02954B48")
-      ("get-byte" "D-0064")
-      ("get-char" "D-0067")
-      ("get-error" "D-0033")
-      ("get-error-str" "D-0010")
+      ("get-byte" "D-0067")
+      ("get-char" "D-0064")
+      ("get-error" "D-0032")
+      ("get-error-str" "D-0011")
       ("get-fd" "N-011D42AB")
       ("get-frames" "N-010405DA")
       ("get-hash-userdata" "N-030B41A7")
@@ -934,7 +934,7 @@
       ("handle*" "N-03F7D8B5")
       ("handle-frame" "N-0233BAE3")
       ("handler-bind" "N-00A4ECC9")
-      ("hash" "D-0001")
+      ("hash" "D-0003")
       ("hash-alist" "N-00C9B125")
       ("hash-begin" "N-0225209D")
       ("hash-construct" "N-017E6F4C")
@@ -1053,12 +1053,12 @@
       ("isec" "N-00DFDE76")
       ("isecp" "N-00DFDE76")
       ("isig" "N-0072FF5E")
-      ("isqrt" "D-0038")
+      ("isqrt" "D-0037")
       ("istrip" "N-02391683")
-      ("iter-begin" "D-002E")
+      ("iter-begin" "D-002D")
       ("iter-item" "D-0005")
-      ("iter-more" "D-003E")
-      ("iter-reset" "D-0020")
+      ("iter-more" "D-003D")
+      ("iter-reset" "D-001F")
       ("iter-step" "D-0072")
       ("iterable" "N-01156AE3")
       ("itimer-prof" "N-02B7882A")
@@ -1088,10 +1088,10 @@
       ("kill" "N-0386CCD5")
       ("krs" "N-02D33A4D")
       ("labels" "N-0209307D")
-      ("lambda" "D-002D")
+      ("lambda" "D-002F")
       ("lambda-match" "N-031E43FF")
       ("lambda-set" "N-02FEBA97")
-      ("last" "D-0043")
+      ("last" "D-0044")
       ("lazy-str" "N-02AFF63D")
       ("lazy-str-force" "N-03269DEF")
       ("lazy-str-force-upto" "N-0212FED6")
@@ -1143,7 +1143,7 @@
       ("load-for" "N-0020A085")
       ("load-time" "D-0048")
       ("loff-t" "N-01153D9E")
-      ("log" "D-0047")
+      ("log" "D-0046")
       ("log-alert" "N-035D75EC")
       ("log-auth" "N-0116F48F")
       ("log-authpriv" "N-0116F48F")
@@ -1162,15 +1162,15 @@
       ("log-pid" "N-02371913")
       ("log-user" "N-0116F48F")
       ("log-warning" "N-035D75EC")
-      ("log10" "D-0052")
+      ("log10" "D-0053")
       ("log2" "D-0075")
       ("logand" "D-000E")
       ("logcount" "D-003B")
       ("logior" "D-004C")
-      ("lognot" "D-0012")
+      ("lognot" "D-0010")
       ("lognot1" "N-019541E2")
       ("logtest" "N-00B1548A")
-      ("logtrunc" "D-0076")
+      ("logtrunc" "D-0077")
       ("logxor" "N-02D5AF97")
       ("long" "N-0235F4E4")
       ("long-suffix" "N-00A3183A")
@@ -1277,7 +1277,7 @@
       ("meq" "N-020A0042")
       ("meql" "N-020A0042")
       ("mequal" "N-020A0042")
-      ("merge" "D-005B")
+      ("merge" "D-005A")
       ("merge-delete-package" "N-0160EA2C")
       ("meth" "N-02C216C3")
       ("method" "N-022200C1")
@@ -1324,7 +1324,7 @@
       ("new" "N-0230059D")
       ("new*" "N-021E6FDC")
       ("nexpand-left" "N-00E168FE")
-      ("next" "D-006E")
+      ("next" "D-0070")
       ("next-file" "N-00839D2F")
       ("nf" "N-0267AE6D")
       ("nil" "N-015134D8")
@@ -1335,7 +1335,7 @@
       ("nldly" "N-03BD477F")
       ("nlink-t" "N-01153D9E")
       ("noflsh" "N-0072FF5E")
-      ("none" "D-006D")
+      ("none" "D-0071")
       ("nor" "N-03662D87")
       ("norf" "N-00C18907")
       ("not" "D-006B")
@@ -1377,7 +1377,7 @@
       ("obtain*-block" "N-0102F0EB")
       ("obtain-block" "N-01C791D0")
       ("ocrnl" "N-03BD477F")
-      ("oddp" "D-0039")
+      ("oddp" "D-003A")
       ("ofdel" "N-03BD477F")
       ("off-t" "N-01153D9E")
       ("offsetof" "N-013D0A5C")
@@ -1474,7 +1474,7 @@
       ("placelet" "N-0393C970")
       ("placelet*" "N-0393C970")
       ("plist-to-alist" "N-006E31B5")
-      ("plusp" "D-0069")
+      ("plusp" "D-0068")
       ("poll" "N-0386D39D")
       ("poly" "N-026201AD")
       ("pop" "N-017F39D2")
@@ -1494,7 +1494,7 @@
       ("pprof" "N-018C92AB")
       ("pred" "N-038E636C")
       ("prinl" "N-02FCCE0D")
-      ("print" "D-0046")
+      ("print" "D-0047")
       ("prn" "N-01E7F5F7")
       ("prod" "N-0163FFE2")
       ("prof" "N-004C9B10")
@@ -1525,9 +1525,9 @@
       ("pushhash" "N-022660B2")
       ("pushnew" "N-02C37AB0")
       ("put-buf" "D-0081")
-      ("put-byte" "D-002F")
+      ("put-byte" "D-002E")
       ("put-carray" "N-00737951")
-      ("put-char" "D-0003")
+      ("put-char" "D-0002")
       ("put-json" "N-009C27EF")
       ("put-jsonl" "N-009C27EF")
       ("put-jsons" "N-0124CAE6")
@@ -1538,7 +1538,7 @@
       ("put-strings" "N-0367B282")
       ("pwd" "N-0047F5F6")
       ("qquote" "N-01665185")
-      ("qref" "D-0070")
+      ("qref" "D-006E")
       ("quantile" "N-0318C018")
       ("quip" "N-03C6D422")
       ("quote" "N-0163F998")
@@ -1660,12 +1660,12 @@
       ("rng-" "N-01A056E4")
       ("rot" "N-025DB962")
       ("rotate" "N-0166291D")
-      ("round" "D-0002")
+      ("round" "D-0004")
       ("round-rem" "N-02DE978F")
       ("round1" "N-03EA1351")
       ("rperm" "N-0188EBDE")
       ("rplaca" "D-004E")
-      ("rplacd" "D-0009")
+      ("rplacd" "D-000A")
       ("rpoly" "N-026201AD")
       ("rpos" "N-01F68300")
       ("rpos-if" "N-01F68300")
@@ -1712,7 +1712,7 @@
       ("seq-next" "N-02E3D643")
       ("seq-reset" "N-01CA6912")
       ("seqp" "N-03C6CAE0")
-      ("set" "D-0015")
+      ("set" "D-0016")
       ("set-cflags" "N-02061924")
       ("set-hash-userdata" "N-030B40A7")
       ("set-iflags" "N-02061924")
@@ -1794,10 +1794,10 @@
       ("sig-winch" "N-0176430F")
       ("sig-xcpu" "N-0176430F")
       ("sig-xfsz" "N-0176430F")
-      ("sign-extend" "D-0031")
-      ("signum" "D-000F")
+      ("sign-extend" "D-0033")
+      ("signum" "D-0012")
       ("sin" "D-000B")
-      ("sinh" "D-0068")
+      ("sinh" "D-0069")
       ("sixth" "N-01B0FA33")
       ("size-t" "N-01B6F219")
       ("size-vec" "N-01000634")
@@ -1864,8 +1864,8 @@
       ("split-str" "N-000386B4")
       ("split-str-set" "N-0296195B")
       ("spln" "N-026FC0BD")
-      ("sqrt" "D-0027")
-      ("square" "D-0032")
+      ("sqrt" "D-0025")
+      ("square" "D-0031")
       ("ssize-t" "N-01153D9E")
       ("sspl" "N-0296195B")
       ("sssucc" "N-038E636C")
@@ -1878,7 +1878,7 @@
       ("static-slot-p" "N-032FD510")
       ("static-slot-set" "N-0017D1B5")
       ("stdlib" "N-008E4BC2")
-      ("str" "D-005F")
+      ("str" "D-005E")
       ("str-addr" "N-02E1B78B")
       ("str-buf" "N-012BF6AD")
       ("str-d" "N-01736060")
@@ -1967,7 +1967,7 @@
       ("take-until" "N-01E42C4C")
       ("take-while" "N-01E42C4C")
       ("tan" "D-003C")
-      ("tanh" "D-0063")
+      ("tanh" "D-0062")
       ("tb" "N-02AB6E53")
       ("tc" "N-029B6E53")
       ("tcdrain" "N-01AC4760")
@@ -2000,7 +2000,7 @@
       ("test-set-indent-mode" "N-01A1F89C")
       ("tf" "N-007E0508")
       ("third" "N-01B0FA33")
-      ("throw" "D-0053")
+      ("throw" "D-0054")
       ("throwf" "N-015466AD")
       ("time" "D-0034")
       ("time-fields-local" "N-00789418")
@@ -2124,7 +2124,7 @@
       ("unless" "N-017EFAB6")
       ("unquote" "N-036B313D")
       ("unsetenv" "N-002E0364")
-      ("until" "D-0025")
+      ("until" "D-0027")
       ("until*" "N-01F7BF0B")
       ("untrace" "N-02833733")
       ("unuse-package" "N-024BF63F")
@@ -2198,7 +2198,7 @@
       ("while-match-case" "N-007220BC")
       ("while-true-match-case" "N-007220BC")
       ("whilet" "N-0154DC75")
-      ("width" "D-0019")
+      ("width" "D-001C")
       ("width-check" "N-01A9EA49")
       ("window-map" "N-015AFD48")
       ("window-mapdo" "N-015AFD48")
@@ -2235,6 +2235,6 @@
       ("zarray" "N-017039ED")
       ("zchar" "N-0008D7DC")
       ("zero-fill" "N-016D3BB5")
-      ("zerop" "D-003F")
+      ("zerop" "D-003E")
       ("zip" "N-03AA85AD")
       ("znew" "N-00B1FC38"))))
diff --git a/stdlib/optimize.tl b/stdlib/optimize.tl
index 8ab9e7ca..ff256db7 100644
--- a/stdlib/optimize.tl
+++ b/stdlib/optimize.tl
@@ -351,15 +351,20 @@
       ((equal sub list) list)
       (t (set [bb.li-hash sub] li) sub))))
 
-(defmeth basic-blocks peephole-block (bb bl code)
+(defmeth basic-blocks rename (bb insns dst src)
+  (mapcar (op subst-preserve dst src bb [bb.li-hash @1] @1) insns))
+
+(defmeth basic-blocks peephole-block (bb bl)
+  (let ((code bb.(do-peephole-block bl bl.insns)))
+    (set bl.insns code)))
+
+(defmeth basic-blocks do-peephole-block (bb bl code)
   (labels ((dead-treg (insn n)
              (let ((li [bb.li-hash insn]))
                (and li (not (bit li.used n)))))
            (only-locally-used-treg (insn n)
              (let ((li [bb.li-hash insn]))
-               (and li (bit li.used n) (not (bit bl.live n)))))
-           (rename (insns dst src)
-             (mapcar (op subst-preserve dst src bb [bb.li-hash @1] @1) insns)))
+               (and li (bit li.used n) (not (bit bl.live n))))))
     (rewrite-case insns code
       ;; dead t-reg
       (@(require ((@(or mov getlx getv getf getfb) (t @n) . @nil) . @nil)
@@ -389,7 +394,7 @@
                  (not (find src rest : [chain bb.li-hash .def])))
         (pushnew bl bb.rescan)
         (set bb.recalc t)
-        (rename rest dst src))
+        bb.(rename rest dst src))
       ;; wasteful moves
       (((mov @reg0 @nil) (mov @reg0 @nil) . @nil)
        (cdr insns))
@@ -476,7 +481,7 @@
 
 (defmeth basic-blocks peephole (bb)
   (each ((bl bb.list))
-    (set bl.insns bb.(peephole-block bl bl.insns)))
+    bb.(peephole-block bl))
   (whilet ((rescan (zap bb.rescan)))
     (whilet ((bl (pop bb.tryjoin)))
       (let ((nxbl bl.next))
@@ -490,7 +495,7 @@
     (when (zap bb.recalc)
       bb.(calc-liveness rescan))
     (each ((bl rescan))
-      (set bl.insns bb.(peephole-block bl bl.insns))))
+      bb.(peephole-block bl)))
  (when bb.reelim
    bb.(elim-dead-code)))