I noticed we sometimes lose range information in forwprop due to a few
match and simplify patterns optimizing away casts. So the easier way
to these cases is to add a match for zero_one_valued_p wich mathes
a cast from another zero_one_valued_p.
This also adds the case of `x & zero_one_valued_p` as being zero_one_valued_p
which allows catching more cases too.
OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.
gcc/ChangeLog:
* match.pd (zero_one_valued_p): Match a cast from a zero_one_valued_p.
Also match `a & zero_one_valued_p` too.
gcc/testsuite/ChangeLog:
* gcc.dg/tree-ssa/bool-13.c: Update testcase as we now do
the MIN/MAX during forwprop1.
---
gcc/match.pd | 10 ++++++++++
gcc/testsuite/gcc.dg/tree-ssa/bool-13.c | 15 +++++----------
2 files changed, 15 insertions(+), 10 deletions(-)
diff --git a/gcc/match.pd b/gcc/match.pd
index 97db0eb5f25..39c9c81966a 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -2181,6 +2181,16 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
&& (TYPE_UNSIGNED (type)
|| TYPE_PRECISION (type) > 1))))
+/* (a&1) is always [0,1] too. This is useful again when
+ the range is not known. */
+(match zero_one_valued_p
+ (bit_and:c@0 @1 zero_one_valued_p))
+
+/* A conversion from an zero_one_valued_p is still a [0,1].
+ This is useful when the range of a variable is not known */
+(match zero_one_valued_p
+ (convert@0 zero_one_valued_p))
+
/* Transform { 0 or 1 } * { 0 or 1 } into { 0 or 1 } & { 0 or 1 }. */
(simplify
(mult zero_one_valued_p@0 zero_one_valued_p@1)
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/bool-13.c
b/gcc/testsuite/gcc.dg/tree-ssa/bool-13.c
index 438f15a484a..de8c99a7727 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/bool-13.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/bool-13.c
@@ -1,5 +1,5 @@
/* { dg-do compile } */
-/* { dg-options "-O1 -fdump-tree-optimized -fdump-tree-original
-fdump-tree-phiopt1 -fdump-tree-forwprop2" } */
+/* { dg-options "-O1 -fdump-tree-optimized -fdump-tree-original
-fdump-tree-forwprop1 -fdump-tree-forwprop2" } */
#define bool _Bool
int maxbool(bool ab, bool bb)
{
@@ -22,15 +22,10 @@ int minbool(bool ab, bool bb)
/* { dg-final { scan-tree-dump-times "MIN_EXPR" 1 "original" } } */
/* { dg-final { scan-tree-dump-times "if " 0 "original" } } */
-/* PHI-OPT1 should have kept it as min/max. */
-/* { dg-final { scan-tree-dump-times "MAX_EXPR" 1 "phiopt1" } } */
-/* { dg-final { scan-tree-dump-times "MIN_EXPR" 1 "phiopt1" } } */
-/* { dg-final { scan-tree-dump-times "if " 0 "phiopt1" } } */
-
-/* Forwprop2 (after ccp) will convert it into &\| */
-/* { dg-final { scan-tree-dump-times "MAX_EXPR" 0 "forwprop2" } } */
-/* { dg-final { scan-tree-dump-times "MIN_EXPR" 0 "forwprop2" } } */
-/* { dg-final { scan-tree-dump-times "if " 0 "forwprop2" } } */
+/* Forwprop1 will convert it into &\| as we can detect that the arguments are
one_zero. */
+/* { dg-final { scan-tree-dump-times "MAX_EXPR" 0 "forwprop1" } } */
+/* { dg-final { scan-tree-dump-times "MIN_EXPR" 0 "forwprop1" } } */
+/* { dg-final { scan-tree-dump-times "if " 0 "forwprop1" } } */
/* By optimize there should be no min/max nor if */
/* { dg-final { scan-tree-dump-times "MAX_EXPR" 0 "optimized" } } */
--
2.31.1
