From 043b6d5377b8b9f6672f039c08f877e464f73c61 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Lindqvist?= <bjourne@gmail.com>
Date: Sun, 12 Apr 2015 06:00:06 +0200
Subject: [PATCH] compiler.cfg.linear-scan.linear-scan: refactoring of word so
 that locals doesn't need to be used and more docs (by moving comments)

---
 .../assignment/assignment-tests.factor        |  5 +++
 .../linear-scan/assignment/assignment.factor  | 10 ++---
 .../cfg/linear-scan/linear-scan-docs.factor   | 13 +++++++
 .../cfg/linear-scan/linear-scan.factor        | 38 ++++++-------------
 4 files changed, 35 insertions(+), 31 deletions(-)

diff --git a/basis/compiler/cfg/linear-scan/assignment/assignment-tests.factor b/basis/compiler/cfg/linear-scan/assignment/assignment-tests.factor
index 7f71bb45cd..5c92db23b7 100644
--- a/basis/compiler/cfg/linear-scan/assignment/assignment-tests.factor
+++ b/basis/compiler/cfg/linear-scan/assignment/assignment-tests.factor
@@ -37,3 +37,8 @@ IN: compiler.cfg.linear-scan.assignment.tests
     pending-interval-heap set 90 expire-old-intervals
     pending-interval-heap get heap-size
 ] unit-test
+
+{ } [
+    V{ T{ ##inc { loc D 3 } { insn# 7 } } } 0 insns>block block>cfg { }
+    assign-registers
+] unit-test
diff --git a/basis/compiler/cfg/linear-scan/assignment/assignment.factor b/basis/compiler/cfg/linear-scan/assignment/assignment.factor
index f0f9739bbc..03e6b19768 100644
--- a/basis/compiler/cfg/linear-scan/assignment/assignment.factor
+++ b/basis/compiler/cfg/linear-scan/assignment/assignment.factor
@@ -136,9 +136,9 @@ M: insn assign-registers-in-insn drop ;
     } cleave ;
 
 :: assign-registers-in-block ( bb -- )
+    bb begin-block
     bb [
         [
-            bb begin-block
             [
                 {
                     [ insn#>> 1 - prepare-insn ]
@@ -147,11 +147,11 @@ M: insn assign-registers-in-insn drop ;
                     [ , ]
                 } cleave
             ] each
-            bb compute-live-out
         ] V{ } make
-    ] change-instructions drop ;
+    ] change-instructions drop
+    bb compute-live-out ;
 
-: assign-registers ( live-intervals cfg -- )
-    [ init-assignment ] dip
+: assign-registers ( cfg live-intervals -- )
+    init-assignment
     linearization-order [ kill-block?>> not ] filter
     [ assign-registers-in-block ] each ;
diff --git a/basis/compiler/cfg/linear-scan/linear-scan-docs.factor b/basis/compiler/cfg/linear-scan/linear-scan-docs.factor
index 5cb837a72a..15ef0e7635 100644
--- a/basis/compiler/cfg/linear-scan/linear-scan-docs.factor
+++ b/basis/compiler/cfg/linear-scan/linear-scan-docs.factor
@@ -4,3 +4,16 @@ IN: compiler.cfg.linear-scan
 HELP: admissible-registers
 { $values { "cfg" cfg } { "regs" assoc } }
 { $description "Lists all registers usable by the cfg by register class. In general, that's all registers except the frame pointer register that might be used by the cfg for other purposes." } ;
+
+ARTICLE: "compiler.cfg.linear-scan" "Linear-scan register allocation"
+"Linear scan to assign physical registers. SSA liveness must have been computed already."
+$nl
+"References:"
+{ $list
+  "Linear Scan Register Allocation by Massimiliano Poletto and Vivek Sarkar http://www.cs.ucla.edu/~palsberg/course/cs132/linearscan.pdf"
+  "Linear Scan Register Allocation for the Java HotSpot Client Compiler by Christian Wimmer and http://www.ssw.uni-linz.ac.at/Research/Papers/Wimmer04Master/"
+  "Quality and Speed in Linear-scan Register Allocation by Omri Traub, Glenn Holloway, Michael D. Smith http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.34.8435"
+} ;
+
+
+ABOUT: "compiler.cfg.linear-scan"
diff --git a/basis/compiler/cfg/linear-scan/linear-scan.factor b/basis/compiler/cfg/linear-scan/linear-scan.factor
index e30f12fd0a..d444427a67 100644
--- a/basis/compiler/cfg/linear-scan/linear-scan.factor
+++ b/basis/compiler/cfg/linear-scan/linear-scan.factor
@@ -4,37 +4,23 @@ USING: accessors assocs compiler.cfg.linear-scan.allocation
 compiler.cfg.linear-scan.assignment
 compiler.cfg.linear-scan.live-intervals
 compiler.cfg.linear-scan.numbering
-compiler.cfg.linear-scan.resolve cpu.architecture kernel locals
-sequences ;
+compiler.cfg.linear-scan.resolve compiler.cfg.utilities cpu.architecture
+kernel sequences ;
 IN: compiler.cfg.linear-scan
 
-! References:
-
-! Linear Scan Register Allocation
-! by Massimiliano Poletto and Vivek Sarkar
-! http://www.cs.ucla.edu/~palsberg/course/cs132/linearscan.pdf
-
-! Linear Scan Register Allocation for the Java HotSpot Client Compiler
-! by Christian Wimmer
-! and http://www.ssw.uni-linz.ac.at/Research/Papers/Wimmer04Master/
-
-! Quality and Speed in Linear-scan Register Allocation
-! by Omri Traub, Glenn Holloway, Michael D. Smith
-! http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.34.8435
-
-! SSA liveness must have been computed already
-
-:: (linear-scan) ( cfg machine-registers -- )
-    cfg number-instructions
-    cfg compute-live-intervals machine-registers allocate-registers
-    cfg assign-registers
-    cfg resolve-data-flow
-    cfg check-numbering ;
-
 : admissible-registers ( cfg -- regs )
     machine-registers swap frame-pointer?>> [
         [ [ frame-reg = not ] filter ] assoc-map
     ] when ;
 
+: allocate-and-assign-registers ( cfg -- )
+    [ ] [ compute-live-intervals ] [ admissible-registers ] tri
+    allocate-registers assign-registers ;
+
 : linear-scan ( cfg -- )
-    dup admissible-registers (linear-scan) ;
+    {
+        number-instructions
+        allocate-and-assign-registers
+        resolve-data-flow
+        check-numbering
+    } apply-passes ;