From 6ed62fe94531f2e56c58d1d7891e099de0a26663 Mon Sep 17 00:00:00 2001 From: Quentin Carbonneaux Date: Wed, 9 Nov 2016 22:34:05 -0500 Subject: doc nits --- doc/Makefile | 2 +- doc/il.txt | 10 +++++----- 2 files changed, 6 insertions(+), 6 deletions(-) diff --git a/doc/Makefile b/doc/Makefile index 60129d6..6fc15e4 100644 --- a/doc/Makefile +++ b/doc/Makefile @@ -14,7 +14,7 @@ html/%.html: %.txt mkdir html 2> /dev/null || true ( echo ''; \ echo ''; \ - echo ''; \ + echo ''; \ echo ''; \ sed -ne '2{s,.*,&,;p;q}' $<; \ echo '
'; \ diff --git a/doc/il.txt b/doc/il.txt index 51525d7..865b81f 100644 --- a/doc/il.txt +++ b/doc/il.txt @@ -761,7 +761,7 @@ will be correctly compiled by QBE. @end ret %s -Now, if you want to know what a phi instruction is and how +Now, if you want to know what phi instructions are and how to use them in QBE, you can read the following. Phi instructions are specific to SSA form. In SSA form @@ -791,10 +791,10 @@ translate it in SSA form is to insert a phi instruction. %y =w phi @ift 1, @iff 2 ret %y -The phi in the example expresses a choice depending on -which block the control came from. When the `@ift` block -is taken, the phi instruction defining `%y` selects 1; -if `@iff` is taken, 2 is selected. +Phi instructions return one of their arguments depending +on where the control came from. In the example, `%y` is +set to 1 if the `@ift` branch is taken, and it is set to +2 otherwise. An important remark about phi instructions is that QBE assumes that if a variable is defined by a phi it respects -- cgit 1.4.1