> The middle-end, testsuite and boilerplate changes in the FEs are ok.
Thanks. But it turns out that the Ada compiler needs a way to convey a pragma
unroll without explicit unrolling factor, because otherwise the RTL unroller
will happily try to unroll some loops USHRT_MAX times...
Tested on x86_64-suse-linux, applied on the mainline.
> Pragma support in the FEs need FE maintainer approval.
Yes, I have posted separate patches for the C/C++ and Fortran front-ends.
2017-11-27 Eric Botcazou <ebotca...@adacore.com>
* cfgloop.h (struct loop): Document usage of USHRT_MAX for unroll.
* loop-unroll.c (decide_unroll_constant_iterations): Implement it.
(decide_unroll_runtime_iterations): Likewise.
(decide_unroll_stupid): Likewise.
2017-11-27 Eric Botcazou <ebotca...@adacore.com>
* gnat.dg/unroll1.ads: Remove alignment clause.
* gnat.dg/unroll2.ads: Likewise.
* gnat.dg/unroll3.ads: Likewise.
* gnat.dg/unroll1.adb: Remove bogus comment terminator.
* gnat.dg/unroll2.adb: Likewise.
* gnat.dg/unroll3.adb: Likewise.
* gnat.dg/unroll4.ad[sb]: New testcase.
* gnat.dg/unroll4_pkg.ads: New helper.
--
Eric BotcazouIndex: cfgloop.h
===================================================================
--- cfgloop.h (revision 255147)
+++ cfgloop.h (working copy)
@@ -221,9 +221,10 @@ struct GTY ((chain_next ("%h.next"))) lo
/* True if the loop is part of an oacc kernels region. */
unsigned in_oacc_kernels_region : 1;
- /* The number of times to unroll the loop. 0, means no information
- given, just do what we always do. A value of 1, means don't unroll
- the loop. */
+ /* The number of times to unroll the loop. 0 means no information given,
+ just do what we always do. A value of 1 means do not unroll the loop.
+ A value of USHRT_MAX means unroll with no specific unrolling factor.
+ Other values means unroll with the given unrolling factor. */
unsigned short unroll;
/* For SIMD loops, this is a unique identifier of the loop, referenced
Index: loop-unroll.c
===================================================================
--- loop-unroll.c (revision 255147)
+++ loop-unroll.c (working copy)
@@ -395,7 +395,7 @@ decide_unroll_constant_iterations (struc
}
/* Check for an explicit unrolling factor. */
- if (loop->unroll)
+ if (loop->unroll > 0 && loop->unroll < USHRT_MAX)
{
/* However we cannot unroll completely at the RTL level a loop with
constant number of iterations; it should have been peeled instead. */
@@ -693,7 +693,7 @@ decide_unroll_runtime_iterations (struct
if (targetm.loop_unroll_adjust)
nunroll = targetm.loop_unroll_adjust (nunroll, loop);
- if (loop->unroll)
+ if (loop->unroll > 0 && loop->unroll < USHRT_MAX)
nunroll = loop->unroll;
/* Skip big loops. */
@@ -1177,7 +1177,7 @@ decide_unroll_stupid (struct loop *loop,
if (targetm.loop_unroll_adjust)
nunroll = targetm.loop_unroll_adjust (nunroll, loop);
- if (loop->unroll)
+ if (loop->unroll > 0 && loop->unroll < USHRT_MAX)
nunroll = loop->unroll;
/* Skip big loops. */
Index: testsuite/gnat.dg/unroll1.adb
===================================================================
--- testsuite/gnat.dg/unroll1.adb (revision 255147)
+++ testsuite/gnat.dg/unroll1.adb (working copy)
@@ -23,5 +23,5 @@ package body Unroll1 is
end Unroll1;
--- { dg-final { scan-tree-dump-times "Not unrolling loop .: user didn't want it unrolled completely" 2 "cunrolli" } } */
--- { dg-final { scan-rtl-dump-times "Not unrolling loop, user didn't want it unrolled" 2 "loop2_unroll" } } */
+-- { dg-final { scan-tree-dump-times "Not unrolling loop .: user didn't want it unrolled completely" 2 "cunrolli" } }
+-- { dg-final { scan-rtl-dump-times "Not unrolling loop, user didn't want it unrolled" 2 "loop2_unroll" } }
Index: testsuite/gnat.dg/unroll1.ads
===================================================================
--- testsuite/gnat.dg/unroll1.ads (revision 255147)
+++ testsuite/gnat.dg/unroll1.ads (working copy)
@@ -1,7 +1,6 @@
package Unroll1 is
type Sarray is array (1 .. 4) of Float;
- for Sarray'Alignment use 16;
function "+" (X, Y : Sarray) return Sarray;
procedure Add (X, Y : Sarray; R : out Sarray);
Index: testsuite/gnat.dg/unroll2.adb
===================================================================
--- testsuite/gnat.dg/unroll2.adb (revision 255147)
+++ testsuite/gnat.dg/unroll2.adb (working copy)
@@ -23,4 +23,4 @@ package body Unroll2 is
end Unroll2;
--- { dg-final { scan-tree-dump-times "note: loop with 3 iterations completely unrolled" 2 "cunrolli" } } */
+-- { dg-final { scan-tree-dump-times "note: loop with 3 iterations completely unrolled" 2 "cunrolli" } }
Index: testsuite/gnat.dg/unroll2.ads
===================================================================
--- testsuite/gnat.dg/unroll2.ads (revision 255147)
+++ testsuite/gnat.dg/unroll2.ads (working copy)
@@ -1,7 +1,6 @@
package Unroll2 is
type Sarray is array (1 .. 4) of Float;
- for Sarray'Alignment use 16;
function "+" (X, Y : Sarray) return Sarray;
procedure Add (X, Y : Sarray; R : out Sarray);
Index: testsuite/gnat.dg/unroll3.adb
===================================================================
--- testsuite/gnat.dg/unroll3.adb (revision 255147)
+++ testsuite/gnat.dg/unroll3.adb (working copy)
@@ -23,4 +23,4 @@ package body Unroll3 is
end Unroll3;
--- { dg-final { scan-tree-dump-times "note: loop with 3 iterations completely unrolled" 2 "cunroll" } } */
+-- { dg-final { scan-tree-dump-times "note: loop with 3 iterations completely unrolled" 2 "cunroll" } }
Index: testsuite/gnat.dg/unroll3.ads
===================================================================
--- testsuite/gnat.dg/unroll3.ads (revision 255147)
+++ testsuite/gnat.dg/unroll3.ads (working copy)
@@ -1,7 +1,6 @@
package Unroll3 is
type Sarray is array (1 .. 4) of Float;
- for Sarray'Alignment use 16;
function "+" (X, Y : Sarray) return Sarray;
procedure Add (X, Y : Sarray; R : out Sarray);
Index: testsuite/gnat.dg/unroll4.adb
===================================================================
--- testsuite/gnat.dg/unroll4.adb (revision 0)
+++ testsuite/gnat.dg/unroll4.adb (working copy)
@@ -0,0 +1,26 @@
+-- { dg-do compile }
+-- { dg-options "-O -fdump-rtl-loop2_unroll-details" }
+
+package body Unroll4 is
+
+ function "+" (X, Y : Sarray) return Sarray is
+ R : Sarray;
+ begin
+ for I in Sarray'Range loop
+ pragma Loop_Optimize (Unroll);
+ R(I) := X(I) + Y(I);
+ end loop;
+ return R;
+ end;
+
+ procedure Add (X, Y : Sarray; R : out Sarray) is
+ begin
+ for I in Sarray'Range loop
+ pragma Loop_Optimize (Unroll);
+ R(I) := X(I) + Y(I);
+ end loop;
+ end;
+
+end Unroll4;
+
+-- { dg-final { scan-rtl-dump-times "note: loop unrolled 7 times" 2 "loop2_unroll" } }
Index: testsuite/gnat.dg/unroll4.ads
===================================================================
--- testsuite/gnat.dg/unroll4.ads (revision 0)
+++ testsuite/gnat.dg/unroll4.ads (working copy)
@@ -0,0 +1,10 @@
+with Unroll4_Pkg; use Unroll4_Pkg;
+
+package Unroll4 is
+
+ type Sarray is array (1 .. N) of Float;
+
+ function "+" (X, Y : Sarray) return Sarray;
+ procedure Add (X, Y : Sarray; R : out Sarray);
+
+end Unroll4;
Index: testsuite/gnat.dg/unroll4_pkg.ads
===================================================================
--- testsuite/gnat.dg/unroll4_pkg.ads (revision 0)
+++ testsuite/gnat.dg/unroll4_pkg.ads (working copy)
@@ -0,0 +1,5 @@
+package Unroll4_Pkg is
+
+ function N return Positive;
+
+end Unroll4_Pkg;
