On 02/04/13 17:06, Kyrylo Tkachov wrote:
From: Ramana Radhakrishnan [mailto:ramana....@googlemail.com]
Sent: 02 April 2013 11:10
To: Kyrylo Tkachov
Cc: gcc-patches@gcc.gnu.org; Richard Earnshaw; Ramana Radhakrishnan
Subject: Re: [PATCH][ARM] minmax_arithsi for non-canonical operand
order with MINUS operator
On Thu, Mar 21, 2013 at 6:09 PM, Kyrylo Tkachov
<kyrylo.tkac...@arm.com> wrote:
Hi all,
This patch adds a splitter variant of the minmax_arithsi pattern for
when
the operator
is non-commutative (MINUS) and the ordering of the operands is not
canonical.
That is, it will trigger for:
#define MAX(a, b) (a > b ? a : b)
int
foo (int a, int b, int c)
{
return c - MAX (a,b);
}
and will generate:
cmp r1, r0
rsbge r0, r1, r2
rsblt r0, r0, r2
instead of the current:
cmp r0, r1
movlt r0, r1
rsb r0, r0, r2
No regressions on arm-none-eabi.
Ok for trunk?
Split after reload please into cond-exec or use if_then_else instead
if you are splitting before reload - I originally thought it to be
safe when you asked me, but then have gone back and corrected myself.
Read this thread . http://patches.linaro.org/6469/ .
Hi Ramana, thanks for the review.
How about this? We split after reload now.
Using if_then_else got me a lot of unrecognisable instruction ICEs and
delaying the split till after reload seemed like a cleaner approach.
Tested arm-none-eabi on qemu.
gcc/
2013-04-02 Kyrylo Tkachov <kyrylo.tkac...@arm.com>
* config/arm/arm.md (minmax_arithsi_non_canon): New pattern.
gcc/testsuite
2013-04-02 Kyrylo Tkachov <kyrylo.tkac...@arm.com>
* gcc.target/arm/minmax_minus.c: New test.
OK.
R.
