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authorgerald <gerald@138bc75d-0d04-0410-961f-82ee72b054a4>2003-09-12 15:52:24 +0000
committergerald <gerald@138bc75d-0d04-0410-961f-82ee72b054a4>2003-09-12 15:52:24 +0000
commit83830f3f448b39170f77006edab89ae41771df12 (patch)
tree3118565d418d8c3dec247ae4893d74bcb1107617 /gcc/loop.c
parent01c05d27f566eac1d3e1158780ba23535ef0fe06 (diff)
downloadppe42-gcc-83830f3f448b39170f77006edab89ae41771df12.tar.gz
ppe42-gcc-83830f3f448b39170f77006edab89ae41771df12.zip
* loop.c: Move comments describing BIV's and GIV's to top of file
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@71333 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/loop.c')
-rw-r--r--gcc/loop.c20
1 files changed, 10 insertions, 10 deletions
diff --git a/gcc/loop.c b/gcc/loop.c
index 31592fc2ba1..2866ce0cb4b 100644
--- a/gcc/loop.c
+++ b/gcc/loop.c
@@ -22,8 +22,16 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
/* This is the loop optimization pass of the compiler.
It finds invariant computations within loops and moves them
to the beginning of the loop. Then it identifies basic and
- general induction variables. Strength reduction is applied to the general
- induction variables, and induction variable elimination is applied to
+ general induction variables.
+
+ Basic induction variables (BIVs) are a pseudo registers which are set within
+ a loop only by incrementing or decrementing its value. General induction
+ variables (GIVs) are pseudo registers with a value which is a linear function
+ of a basic induction variable. BIVs are recognized by `basic_induction_var';
+ GIVs by `general_induction_var'.
+
+ Once induction variables are identified, strength reduction is applied to the
+ general induction variables, and induction variable elimination is applied to
the basic induction variables.
It also finds cases where
@@ -4223,14 +4231,6 @@ emit_prefetch_instructions (struct loop *loop)
return;
}
-/* A "basic induction variable" or biv is a pseudo reg that is set
- (within this loop) only by incrementing or decrementing it. */
-/* A "general induction variable" or giv is a pseudo reg whose
- value is a linear function of a biv. */
-
-/* Bivs are recognized by `basic_induction_var';
- Givs by `general_induction_var'. */
-
/* Communication with routines called via `note_stores'. */
static rtx note_insn;
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