procyberian/gcc
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

re PR rtl-optimization/16001 (unable to find a register to spill in class `AREG' (-O2 -funroll-loops))

Browse source 
PR rtl-optimization/16001
	* loop-iv.c (iv_number_of_iterations): Prevent copy propagation in
	niter_expr.

From-SVN: r84486
This commit is contained in:
Zdenek Dvorak 2004-07-11 04:52:54 +02:00 • committed by Zdenek Dvorak
parent ef262483b8
commit fe3f617f6d
2 changed files with 23 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

7
gcc/ChangeLog
View file

@ -1,3 +1,9 @@
2004-07-10 Zdenek Dvorak <rakdver@atrey.karlin.mff.cuni.cz>
PR rtl-optimization/16001
* loop-iv.c (iv_number_of_iterations): Prevent copy propagation in
niter_expr.
2004-07-10 Geoffrey Keating <geoffk@apple.com>
* config/darwin.h (LINK_COMMAND_SPEC): Don't call c++filt.
@ -10,6 +16,7 @@
2004-07-10 Zdenek Dvorak <rakdver@atrey.karlin.mff.cuni.cz>
PR rtl-optimization/15387
* calls.c (check_sibcall_argument_overlap_1): Handle pointers
to incoming args space correctly.

18
gcc/loop-iv.c
View file

@ -1967,6 +1967,7 @@ iv_number_of_iterations (struct loop *loop, rtx insn, rtx condition,
unsigned HOST_WIDEST_INT s, size, d, inv;
HOST_WIDEST_INT up, down, inc;
int was_sharp = false;
rtx old_niter;
/* The meaning of these assumptions is this:
if !assumptions
@ -2366,6 +2367,8 @@ iv_number_of_iterations (struct loop *loop, rtx insn, rtx condition,
desc->niter_expr = delta;
}
old_niter = desc->niter_expr;
simplify_using_initial_values (loop, AND, &desc->assumptions);
if (desc->assumptions
&& XEXP (desc->assumptions, 0) == const0_rtx)
@ -2408,8 +2411,19 @@ iv_number_of_iterations (struct loop *loop, rtx insn, rtx condition,
desc->const_iter = true;
desc->niter_max = desc->niter = val & GET_MODE_MASK (desc->mode);
}
else if (!desc->niter_max)
desc->niter_max = determine_max_iter (desc);
else
{
if (!desc->niter_max)
desc->niter_max = determine_max_iter (desc);
/* simplify_using_initial_values does a copy propagation on the registers
in the expression for the number of iterations. This prolongs life
ranges of registers and increases register pressure, and usually
brings no gain (and if it happens to do, the cse pass will take care
of it anyway). So prevent this behavior, unless it enabled us to
derive that the number of iterations is a constant. */
desc->niter_expr = old_niter;
}
return;