`(a == CST) & a` can be either simplified to simplying `a == CST`
or 0 depending on the first bit of the CST.
This is an extension of the already pattern of `X & !X` and allows
us to remove the 2 xfails on gcc.dg/binop-notand1a.c and
gcc.dg/binop-notand4a.c.
OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.
PR tree-optimization/111431
gcc/ChangeLog:
* match.pd (`(a == CST) & a`): New pattern.
gcc/testsuite/ChangeLog:
* gcc.dg/binop-notand1a.c: Remove xfail.
* gcc.dg/binop-notand4a.c: Likewise.
* gcc.c-torture/execute/pr111431-1.c: New test.
* gcc.dg/binop-andeq1.c: New test.
* gcc.dg/binop-andeq2.c: New test.
* gcc.dg/binop-notand7.c: New test.
* gcc.dg/binop-notand7a.c: New test.
---
gcc/match.pd | 8 ++++
.../gcc.c-torture/execute/pr111431-1.c | 39 +++++++++++++++++++
gcc/testsuite/gcc.dg/binop-andeq1.c | 12 ++++++
gcc/testsuite/gcc.dg/binop-andeq2.c | 14 +++++++
gcc/testsuite/gcc.dg/binop-notand1a.c | 4 +-
gcc/testsuite/gcc.dg/binop-notand4a.c | 4 +-
gcc/testsuite/gcc.dg/binop-notand7.c | 12 ++++++
gcc/testsuite/gcc.dg/binop-notand7a.c | 12 ++++++
8 files changed, 99 insertions(+), 6 deletions(-)
create mode 100644 gcc/testsuite/gcc.c-torture/execute/pr111431-1.c
create mode 100644 gcc/testsuite/gcc.dg/binop-andeq1.c
create mode 100644 gcc/testsuite/gcc.dg/binop-andeq2.c
create mode 100644 gcc/testsuite/gcc.dg/binop-notand7.c
create mode 100644 gcc/testsuite/gcc.dg/binop-notand7a.c
diff --git a/gcc/match.pd b/gcc/match.pd
index ebb50ee0581..65960a1701e 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -5172,6 +5172,14 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
)
)
+/* `(a == CST) & a` can be simplified to `0` or `(a == CST)` depending
+ on the first bit of the CST. */
+(simplify
+ (bit_and:c (convert@2 (eq @0 INTEGER_CST@1)) (convert? @0))
+ (if ((wi::to_wide (@1) & 1) != 0)
+ @2
+ { build_zero_cst (type); }))
+
/* Optimize
# x_5 in range [cst1, cst2] where cst2 = cst1 + 1
x_5 ? cstN ? cst4 : cst3
diff --git a/gcc/testsuite/gcc.c-torture/execute/pr111431-1.c
b/gcc/testsuite/gcc.c-torture/execute/pr111431-1.c
new file mode 100644
index 00000000000..a96dbadf2b5
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/pr111431-1.c
@@ -0,0 +1,39 @@
+int
+foo (int a)
+{
+ int b = a == 0;
+ return (a & b);
+}
+
+#define function(vol,cst) \
+__attribute__((noipa)) \
+_Bool func_##cst##_##vol(vol int a) \
+{ \
+ vol int b = a == cst; \
+ return (a & b); \
+}
+
+#define funcdefs(cst) \
+function(,cst) \
+function(volatile,cst)
+
+#define funcs(f) \
+f(0) \
+f(1) \
+f(5)
+
+funcs(funcdefs)
+
+#define test(cst) \
+do { \
+ if(func_##cst##_(a) != func_##cst##_volatile(a))\
+ __builtin_abort(); \
+} while(0);
+int main(void)
+{
+ for(int a = -10; a <= 10; a++)
+ {
+ funcs(test)
+ }
+}
+
diff --git a/gcc/testsuite/gcc.dg/binop-andeq1.c
b/gcc/testsuite/gcc.dg/binop-andeq1.c
new file mode 100644
index 00000000000..2a92b8f95df
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/binop-andeq1.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+/* PR tree-optimization/111431 */
+
+int
+foo (int a)
+{
+ int b = a == 2;
+ return (a & b);
+}
+
+/* { dg-final { scan-tree-dump-times "return 0" 1 "optimized" } } */
diff --git a/gcc/testsuite/gcc.dg/binop-andeq2.c
b/gcc/testsuite/gcc.dg/binop-andeq2.c
new file mode 100644
index 00000000000..895262fc17e
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/binop-andeq2.c
@@ -0,0 +1,14 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+/* PR tree-optimization/111431 */
+
+int
+foo (int a)
+{
+ int b = a == 1025;
+ return (a & b);
+}
+
+/* { dg-final { scan-tree-dump-not "return 0" "optimized" } } */
+/* { dg-final { scan-tree-dump-not " & " "optimized" } } */
+/* { dg-final { scan-tree-dump-times " == 1025;" 1 "optimized" } } */
diff --git a/gcc/testsuite/gcc.dg/binop-notand1a.c
b/gcc/testsuite/gcc.dg/binop-notand1a.c
index c7e932b2638..d94685eb4ce 100644
--- a/gcc/testsuite/gcc.dg/binop-notand1a.c
+++ b/gcc/testsuite/gcc.dg/binop-notand1a.c
@@ -7,6 +7,4 @@ foo (char a, unsigned short b)
return (a & !a) | (b & !b);
}
-/* As long as comparisons aren't boolified and casts from boolean-types
- aren't preserved, the folding of X & !X to zero fails. */
-/* { dg-final { scan-tree-dump-times "return 0" 1 "optimized" { xfail *-*-* }
} } */
+/* { dg-final { scan-tree-dump-times "return 0" 1 "optimized" } } */
diff --git a/gcc/testsuite/gcc.dg/binop-notand4a.c
b/gcc/testsuite/gcc.dg/binop-notand4a.c
index dce6a5c7eb5..bd9c7cce638 100644
--- a/gcc/testsuite/gcc.dg/binop-notand4a.c
+++ b/gcc/testsuite/gcc.dg/binop-notand4a.c
@@ -7,6 +7,4 @@ foo (unsigned char a, _Bool b)
return (!a & a) | (b & !b);
}
-/* As long as comparisons aren't boolified and casts from boolean-types
- aren't preserved, the folding of X & !X to zero fails. */
-/* { dg-final { scan-tree-dump-times "return 0" 1 "optimized" { xfail *-*-* }
} } */
+/* { dg-final { scan-tree-dump-times "return 0" 1 "optimized" } } */
diff --git a/gcc/testsuite/gcc.dg/binop-notand7.c
b/gcc/testsuite/gcc.dg/binop-notand7.c
new file mode 100644
index 00000000000..c2bb6a0449d
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/binop-notand7.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+/* PR tree-optimization/111431 */
+
+int
+foo (int a)
+{
+ int b = !a;
+ return (a & b);
+}
+
+/* { dg-final { scan-tree-dump-times "return 0" 1 "optimized" } } */
diff --git a/gcc/testsuite/gcc.dg/binop-notand7a.c
b/gcc/testsuite/gcc.dg/binop-notand7a.c
new file mode 100644
index 00000000000..dd50916da61
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/binop-notand7a.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+/* PR tree-optimization/111431 */
+
+unsigned
+foo (int a)
+{
+ int b = !a;
+ return (a & b);
+}
+
+/* { dg-final { scan-tree-dump-times "return 0" 1 "optimized" } } */
--
2.31.1
