[PATCH] MATCH: Simplify (a CMP1 b) ^ (a CMP2 b)

Andrew Pinski apinski@marvell.com
Tue Sep 12 04:21:52 GMT 2023


This adds the missing optimizations here.
Note we don't need to match where CMP1 and CMP2 are complements of each
other as that is already handled elsewhere.

I added a new executable testcase to make sure we optimize it correctly
as I had originally messed up one of the entries for the resulting
comparison to make sure they were 100% correct.

OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.

	PR tree-optimization/107881

gcc/ChangeLog:

	* match.pd (`(a CMP1 b) ^ (a CMP2 b)`): New pattern.
	(`(a CMP1 b) == (a CMP2 b)`): New pattern.

gcc/testsuite/ChangeLog:

	* gcc.c-torture/execute/pr107881-1.c: New test.
	* gcc.dg/tree-ssa/cmpeq-4.c: New test.
	* gcc.dg/tree-ssa/cmpxor-1.c: New test.
---
 gcc/match.pd                                  |  20 +++
 .../gcc.c-torture/execute/pr107881-1.c        | 115 ++++++++++++++++++
 gcc/testsuite/gcc.dg/tree-ssa/cmpeq-4.c       |  51 ++++++++
 gcc/testsuite/gcc.dg/tree-ssa/cmpxor-1.c      |  51 ++++++++
 4 files changed, 237 insertions(+)
 create mode 100644 gcc/testsuite/gcc.c-torture/execute/pr107881-1.c
 create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/cmpeq-4.c
 create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/cmpxor-1.c

diff --git a/gcc/match.pd b/gcc/match.pd
index e96e385c6fa..39c7ea1088f 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -3154,6 +3154,26 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
       { constant_boolean_node (true, type); })
      ))))))
 
+/* Optimize (a CMP b) ^ (a CMP b)  */
+/* Optimize (a CMP b) != (a CMP b)  */
+(for op (bit_xor ne)
+ (for cmp1 (lt lt lt le le le)
+      cmp2 (gt eq ne ge eq ne)
+      rcmp (ne le gt ne lt ge)
+  (simplify
+   (op:c (cmp1:c @0 @1) (cmp2:c @0 @1))
+   (if (INTEGRAL_TYPE_P (TREE_TYPE (@0)) || POINTER_TYPE_P (TREE_TYPE (@0)))
+    (rcmp @0 @1)))))
+
+/* Optimize (a CMP b) == (a CMP b)  */
+(for cmp1 (lt lt lt le le le)
+     cmp2 (gt eq ne ge eq ne)
+     rcmp (eq gt le eq ge lt)
+ (simplify
+  (eq:c (cmp1:c @0 @1) (cmp2:c @0 @1))
+  (if (INTEGRAL_TYPE_P (TREE_TYPE (@0)) || POINTER_TYPE_P (TREE_TYPE (@0)))
+    (rcmp @0 @1))))
+
 /* We can't reassociate at all for saturating types.  */
 (if (!TYPE_SATURATING (type))
 
diff --git a/gcc/testsuite/gcc.c-torture/execute/pr107881-1.c b/gcc/testsuite/gcc.c-torture/execute/pr107881-1.c
new file mode 100644
index 00000000000..063ec4c2797
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/pr107881-1.c
@@ -0,0 +1,115 @@
+#define func(vol, op1, op2, op3)	\
+_Bool op1##_##op2##_##op3##_##vol (int a, int b)	\
+{					\
+ vol _Bool x = op_##op1(a, b);		\
+ vol _Bool y = op_##op2(a, b);		\
+ return op_##op3(x, y);			\
+}
+
+#define op_lt(a, b) ((a) < (b))
+#define op_le(a, b) ((a) <= (b))
+#define op_eq(a, b) ((a) == (b))
+#define op_ne(a, b) ((a) != (b))
+#define op_gt(a, b) ((a) > (b))
+#define op_ge(a, b) ((a) >= (b))
+#define op_xor(a, b) ((a) ^ (b))
+
+
+#define funcs(a) \
+ a(lt,lt,ne) \
+ a(lt,lt,eq) \
+ a(lt,lt,xor) \
+ a(lt,le,ne) \
+ a(lt,le,eq) \
+ a(lt,le,xor) \
+ a(lt,gt,ne) \
+ a(lt,gt,eq) \
+ a(lt,gt,xor) \
+ a(lt,ge,ne) \
+ a(lt,ge,eq) \
+ a(lt,ge,xor) \
+ a(lt,eq,ne) \
+ a(lt,eq,eq) \
+ a(lt,eq,xor) \
+ a(lt,ne,ne) \
+ a(lt,ne,eq) \
+ a(lt,ne,xor) \
+  \
+ a(le,lt,ne) \
+ a(le,lt,eq) \
+ a(le,lt,xor) \
+ a(le,le,ne) \
+ a(le,le,eq) \
+ a(le,le,xor) \
+ a(le,gt,ne) \
+ a(le,gt,eq) \
+ a(le,gt,xor) \
+ a(le,ge,ne) \
+ a(le,ge,eq) \
+ a(le,ge,xor) \
+ a(le,eq,ne) \
+ a(le,eq,eq) \
+ a(le,eq,xor) \
+ a(le,ne,ne) \
+ a(le,ne,eq) \
+ a(le,ne,xor)  \
+ \
+ a(gt,lt,ne) \
+ a(gt,lt,eq) \
+ a(gt,lt,xor) \
+ a(gt,le,ne) \
+ a(gt,le,eq) \
+ a(gt,le,xor) \
+ a(gt,gt,ne) \
+ a(gt,gt,eq) \
+ a(gt,gt,xor) \
+ a(gt,ge,ne) \
+ a(gt,ge,eq) \
+ a(gt,ge,xor) \
+ a(gt,eq,ne) \
+ a(gt,eq,eq) \
+ a(gt,eq,xor) \
+ a(gt,ne,ne) \
+ a(gt,ne,eq) \
+ a(gt,ne,xor) \
+  \
+ a(ge,lt,ne) \
+ a(ge,lt,eq) \
+ a(ge,lt,xor) \
+ a(ge,le,ne) \
+ a(ge,le,eq) \
+ a(ge,le,xor) \
+ a(ge,gt,ne) \
+ a(ge,gt,eq) \
+ a(ge,gt,xor) \
+ a(ge,ge,ne) \
+ a(ge,ge,eq) \
+ a(ge,ge,xor) \
+ a(ge,eq,ne) \
+ a(ge,eq,eq) \
+ a(ge,eq,xor) \
+ a(ge,ne,ne) \
+ a(ge,ne,eq) \
+ a(ge,ne,xor)
+
+#define funcs1(a,b,c) \
+func(,a,b,c) \
+func(volatile,a,b,c)
+
+funcs(funcs1)
+
+#define test(op1,op2,op3)			\
+do {						\
+  if (op1##_##op2##_##op3##_(x,y)		\
+      != op1##_##op2##_##op3##_volatile(x,y))	\
+    __builtin_abort();				\
+} while(0);
+
+int main()
+{
+  for(int x = -10; x < 10; x++)
+    for(int y = -10; y < 10; y++)
+    {
+        funcs(test)
+    }
+}
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/cmpeq-4.c b/gcc/testsuite/gcc.dg/tree-ssa/cmpeq-4.c
new file mode 100644
index 00000000000..868d80fdcca
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/cmpeq-4.c
@@ -0,0 +1,51 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized -fdump-tree-original" } */
+/* PR tree-optimization/107881 */
+
+_Bool ltgt_eq(int a, int b)
+{
+  _Bool c = a < b;
+  _Bool d = a > b;
+  return c == d; // a == b
+}
+/* { dg-final { scan-tree-dump "a_\[0-9\]+.D. == b_\[0-9\]+.D.|b_\[0-9\]+.D. == a_\[0-9\]+.D." "optimized" } } */
+
+_Bool lteq_eq(int x, int y)
+{
+  _Bool c = x < y;
+  _Bool d = x == y;
+  return c == d; // x > y
+}
+/* { dg-final { scan-tree-dump "x_\[0-9\]+.D. > y_\[0-9\]+.D.|y_\[0-9\]+.D. < x_\[0-9\]+.D." "optimized" } } */
+
+_Bool ltne_eq(int z, int w)
+{
+  _Bool c = z < w;
+  _Bool d = z != w;
+  return c == d; // z <= w
+}
+/* { dg-final { scan-tree-dump "z_\[0-9\]+.D. <= w_\[0-9\]+.D.|w_\[0-9\]+.D. >= y_\[0-9\]+.D." "optimized" } } */
+
+_Bool lege_eq(int i, int j)
+{
+  _Bool c = i <= j;
+  _Bool d = i >= j;
+  return c == d; // i == j
+}
+/* { dg-final { scan-tree-dump "i_\[0-9\]+.D. == j_\[0-9\]+.D.|j_\[0-9\]+.D. == i_\[0-9\]+.D." "optimized" } } */
+
+_Bool leeq_eq(int k, int l)
+{
+  _Bool c = k <= l;
+  _Bool d = k == l;
+  return c == d; // k >= l
+}
+/* { dg-final { scan-tree-dump "k_\[0-9\]+.D. >= l_\[0-9\]+.D.|l_\[0-9\]+.D. <= k_\[0-9\]+.D." "optimized" } } */
+
+_Bool lene_eq(int m, int n)
+{
+  _Bool c = m <= n;
+  _Bool d = m != n;
+  return c == d; // m < n
+}
+/* { dg-final { scan-tree-dump "m_\[0-9\]+.D. < n_\[0-9\]+.D.|n_\[0-9\]+.D. > m_\[0-9\]+.D." "optimized" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/cmpxor-1.c b/gcc/testsuite/gcc.dg/tree-ssa/cmpxor-1.c
new file mode 100644
index 00000000000..8de2d9d2244
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/cmpxor-1.c
@@ -0,0 +1,51 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+/* PR tree-optimization/107881 */
+
+_Bool ltgtxor(int a, int b)
+{
+  _Bool c = a < b;
+  _Bool d = a > b;
+  return c ^ d; // a != b
+}
+/* { dg-final { scan-tree-dump "a_\[0-9\]+.D. != b_\[0-9\]+.D.|b_\[0-9\]+.D. != a_\[0-9\]+.D." "optimized" } } */
+
+_Bool lteqxor(int x, int y)
+{
+  _Bool c = x < y;
+  _Bool d = x == y;
+  return c ^ d; // x <= y (basically | here)
+}
+/* { dg-final { scan-tree-dump "x_\[0-9\]+.D. <= y_\[0-9\]+.D.|y_\[0-9\]+.D. >= x_\[0-9\]+.D." "optimized" } } */
+
+_Bool ltnexor(int z, int w)
+{
+  _Bool c = z < w;
+  _Bool d = z != w;
+  return c ^ d; // z > w
+}
+/* { dg-final { scan-tree-dump "z_\[0-9\]+.D. > w_\[0-9\]+.D.|w_\[0-9\]+.D. < y_\[0-9\]+.D." "optimized" } } */
+
+_Bool legexor(int i, int j)
+{
+  _Bool c = i <= j;
+  _Bool d = i >= j;
+  return c ^ d; // i != j
+}
+/* { dg-final { scan-tree-dump "i_\[0-9\]+.D. != j_\[0-9\]+.D.|j_\[0-9\]+.D. != i_\[0-9\]+.D." "optimized" } } */
+
+_Bool leeqxor(int k, int l)
+{
+  _Bool c = k <= l;
+  _Bool d = k == l;
+  return c ^ d; // k < l
+}
+/* { dg-final { scan-tree-dump "k_\[0-9\]+.D. < l_\[0-9\]+.D.|l_\[0-9\]+.D. > k_\[0-9\]+.D." "optimized" } } */
+
+_Bool lenexor(int m, int n)
+{
+  _Bool c = m <= n;
+  _Bool d = m != n;
+  return c ^ d; // m >= n
+}
+/* { dg-final { scan-tree-dump "m_\[0-9\]+.D. >= n_\[0-9\]+.D.|n_\[0-9\]+.D. <= m_\[0-9\]+.D." "optimized" } } */
-- 
2.31.1



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