From ae0b77a0c410da7e171e23c29acd0df2160508e7 Mon Sep 17 00:00:00 2001
From: Alex Vondrak <ajvondrak@gmail.com>
Date: Tue, 25 Dec 2012 09:19:35 -0800
Subject: [PATCH] compiler.cfg.ssa.cssa: split the definitions of ##phis so
live-ranges don't interfere (issue #22)
See the explanation after the proof of Lemma 1 in "Revisiting Out-of-SSA
Translation for Correctness, Code Quality, and Efficiency" (Boissinot et
al.) for why this is necessary.
---
basis/compiler/cfg/ssa/cssa/cssa.factor | 35 ++++++++++++++++++++-----
1 file changed, 29 insertions(+), 6 deletions(-)
diff --git a/basis/compiler/cfg/ssa/cssa/cssa.factor b/basis/compiler/cfg/ssa/cssa/cssa.factor
index 7565be48b8..6c2d6587b9 100644
--- a/basis/compiler/cfg/ssa/cssa/cssa.factor
+++ b/basis/compiler/cfg/ssa/cssa/cssa.factor
@@ -15,19 +15,26 @@ IN: compiler.cfg.ssa.cssa
! selection, so it must keep track of representations when introducing
! new values.
-SYMBOL: copies
+SYMBOLS: edge-copies phi-copies ;
: init-copies ( bb -- )
- predecessors>> [ V{ } clone ] H{ } map>assoc copies set ;
+ V{ } clone phi-copies set
+ predecessors>> [ V{ } clone ] H{ } map>assoc edge-copies set ;
:: convert-operand ( src pred rep -- dst )
rep next-vreg-rep :> dst
- { dst src } pred copies get at push
+ { dst src } pred edge-copies get at push
dst ;
:: convert-phi ( insn preds -- )
- insn dst>> rep-of :> rep
+ insn dst>> :> dst
+ dst rep-of :> rep
insn inputs>> :> inputs
+ rep next-vreg-rep :> dst'
+
+ { dst dst' } phi-copies get push
+ dst' insn dst<<
+
preds [| pred |
pred inputs [ pred rep convert-operand ] change-at
] each ;
@@ -35,11 +42,27 @@ SYMBOL: copies
: insert-edge-copies ( from to copies -- )
[ ##parallel-copy, ##branch, ] { } make insert-basic-block ;
-: insert-copies ( bb -- )
- [ copies get ] dip '[
+: insert-all-edge-copies ( bb -- )
+ [ edge-copies get ] dip '[
[ drop ] [ [ _ ] dip insert-edge-copies ] if-empty
] assoc-each ;
+: phi-copy-insn ( -- insn )
+ phi-copies get f \ ##parallel-copy boa ;
+
+: end-of-phis ( insns -- i )
+ [ [ ##phi? not ] find drop ] [ length ] bi or ;
+
+: insert-phi-copies ( bb -- )
+ [
+ [
+ [ drop phi-copy-insn ] [ end-of-phis ] [ ] tri insert-nth
+ ] change-instructions drop
+ ] if-has-phis ;
+
+: insert-copies ( bb -- )
+ [ insert-all-edge-copies ] [ insert-phi-copies ] bi ;
+
: convert-phis ( bb -- )
[ init-copies ]
[ dup predecessors>> '[ _ convert-phi ] each-phi ]