[PATCH] IBM Z: Remove match_scratch workaround

[PATCH] IBM Z: Remove match_scratch workaround

[Ilya Leoshkevich]

Bootstrapped and regtested on s390x-redhat-linux.  Ok for master?



Since commit dd1ef00c45ba ("Fix bug in the define_subst handling that
made match_scratch unusable for multi-alternative patterns.") the
workaround for that bug in *ashrdi3_31<setcc><cconly> is not only no
longer necessary, but actually breaks the build.

Get rid of it by using only one alternative in (match_scratch).  It
will be replicated as many times as needed in order to match the
pattern with which (define_subst) is used.

gcc/ChangeLog:

	* config/s390/s390.md(*ashrdi3_31<setcc><cconly>): Use a single
	constraint.
	* config/s390/subst.md(cconly_subst): Use a single constraint
	in (match_scratch).

gcc/testsuite/ChangeLog:

	* gcc.target/s390/ashr.c: New test.
---
 gcc/config/s390/s390.md              | 14 ++++----------
 gcc/config/s390/subst.md             |  2 +-
 gcc/testsuite/gcc.target/s390/ashr.c | 11 +++++++++++
 3 files changed, 16 insertions(+), 11 deletions(-)
 create mode 100644 gcc/testsuite/gcc.target/s390/ashr.c

diff --git a/gcc/config/s390/s390.md b/gcc/config/s390/s390.md
index 7faf775fbf2..0c5b4dc9029 100644
--- a/gcc/config/s390/s390.md
+++ b/gcc/config/s390/s390.md
@@ -9328,19 +9328,13 @@
   ""
   "")
 
-; FIXME: The number of alternatives is doubled here to match the fix
-; number of 2 in the subst pattern for the (clobber (match_scratch...
-; The right fix should be to support match_scratch in the output
-; pattern of a define_subst.
 (define_insn "*ashrdi3_31<setcc><cconly>"
-  [(set (match_operand:DI 0 "register_operand"               "=d, d")
-        (ashiftrt:DI (match_operand:DI 1 "register_operand"   "0, 0")
-                     (match_operand:QI 2 "shift_count_operand" "jsc,jsc")))
+  [(set (match_operand:DI 0 "register_operand"               "=d")
+        (ashiftrt:DI (match_operand:DI 1 "register_operand"   "0")
+                     (match_operand:QI 2 "shift_count_operand" "jsc")))
    (clobber (reg:CC CC_REGNUM))]
   "!TARGET_ZARCH"
-  "@
-   srda\t%0,%Y2
-   srda\t%0,%Y2"
+  "srda\t%0,%Y2"
   [(set_attr "op_type" "RS")
    (set_attr "atype"   "reg")])
 
diff --git a/gcc/config/s390/subst.md b/gcc/config/s390/subst.md
index 384af11c198..3ea6fc40ba8 100644
--- a/gcc/config/s390/subst.md
+++ b/gcc/config/s390/subst.md
@@ -45,7 +45,7 @@
   "s390_match_ccmode(insn, CCSmode)"
   [(set (reg CC_REGNUM)
 	(compare (match_dup 1) (const_int 0)))
-   (clobber (match_scratch:DSI 0 "=d,d"))])
+   (clobber (match_scratch:DSI 0 "=d"))])
 
 (define_subst_attr "cconly" "cconly_subst" "" "_cconly")
 
diff --git a/gcc/testsuite/gcc.target/s390/ashr.c b/gcc/testsuite/gcc.target/s390/ashr.c
new file mode 100644
index 00000000000..8cffdfa9a1d
--- /dev/null
+++ b/gcc/testsuite/gcc.target/s390/ashr.c
@@ -0,0 +1,11 @@
+/* Test the arithmetic shift right pattern.  */
+
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+int e(void);
+
+int f (long c, int b)
+{
+  return (c >> b) && e ();
+}
-- 
2.31.1

Re: [PATCH] IBM Z: Remove match_scratch workaround

[Jeff Law]

On 6/1/2021 8:21 PM, Ilya Leoshkevich via Gcc-patches wrote:
> Bootstrapped and regtested on s390x-redhat-linux.  Ok for master?
>
>
>
> Since commit dd1ef00c45ba ("Fix bug in the define_subst handling that
> made match_scratch unusable for multi-alternative patterns.") the
> workaround for that bug in *ashrdi3_31<setcc><cconly> is not only no
> longer necessary, but actually breaks the build.
>
> Get rid of it by using only one alternative in (match_scratch).  It
> will be replicated as many times as needed in order to match the
> pattern with which (define_subst) is used.
>
> gcc/ChangeLog:
>
> 	* config/s390/s390.md(*ashrdi3_31<setcc><cconly>): Use a single
> 	constraint.
> 	* config/s390/subst.md(cconly_subst): Use a single constraint
> 	in (match_scratch).
>
> gcc/testsuite/ChangeLog:
>
> 	* gcc.target/s390/ashr.c: New test.
Presumably this fixes:

../../../gcc/gcc/config/s390/s390.md:9335:1: alternative number mismatch: operand 0 has 4, operand 1 has 2
../../../gcc/gcc/config/s390/s390.md:9335:1: alternative number mismatch: operand 0 has 4, operand 2 has 2
../../../gcc/gcc/config/s390/s390.md:9335:1: wrong number of alternatives in the output template
../../../gcc/gcc/config/s390/s390.md:9349:1: alternative number mismatch: operand 0 has 4, operand 1 has 2
../../../gcc/gcc/config/s390/s390.md:9349:1: alternative number mismatch: operand 0 has 4, operand 2 has 2
../../../gcc/gcc/config/s390/s390.md:9349:1: wrong number of alternatives in the output template
../../../gcc/gcc/config/s390/s390.md:9349:1: alternative number mismatch: operand 0 has 4, operand 1 has 2
../../../gcc/gcc/config/s390/s390.md:9349:1: alternative number mismatch: operand 0 has 4, operand 2 has 2
../../../gcc/gcc/config/s390/s390.md:9349:1: wrong number of alternatives in the output template


The tester has been tripping over that for about a week.

I'll let the s390 maintainers chime in on the correctness of the change.

Jeff

Re: [PATCH] IBM Z: Remove match_scratch workaround

[Andreas Krebbel]

On 6/2/21 4:21 AM, Ilya Leoshkevich wrote:
> Bootstrapped and regtested on s390x-redhat-linux.  Ok for master?
> 
> 
> 
> Since commit dd1ef00c45ba ("Fix bug in the define_subst handling that
> made match_scratch unusable for multi-alternative patterns.") the
> workaround for that bug in *ashrdi3_31<setcc><cconly> is not only no
> longer necessary, but actually breaks the build.
> 
> Get rid of it by using only one alternative in (match_scratch).  It
> will be replicated as many times as needed in order to match the
> pattern with which (define_subst) is used.
> 
> gcc/ChangeLog:
> 
> 	* config/s390/s390.md(*ashrdi3_31<setcc><cconly>): Use a single
> 	constraint.
> 	* config/s390/subst.md(cconly_subst): Use a single constraint
> 	in (match_scratch).
> 
> gcc/testsuite/ChangeLog:
> 
> 	* gcc.target/s390/ashr.c: New test.

Ok. Thanks!

Andreas