[PATCH] Enhance final_value_replacement_loop to handle bitop with an invariant induction.[PR105735]

["Kong, Lingling" <lingling.kong@intel.com>]

Hi,

This patch is for pr105735/pr101991. It will enable below optimization:
{
-  long unsigned int bit;
-
-  <bb 2> [local count: 32534376]:
-
-  <bb 3> [local count: 1041207449]:
-  # tmp_10 = PHI <tmp_7(5), tmp_4(D)(2)>
-  # bit_12 = PHI <bit_8(5), 0(2)>
-  tmp_7 = bit2_6(D) & tmp_10;
-  bit_8 = bit_12 + 1;
-  if (bit_8 != 32)
-    goto <bb 5>; [96.97%]
-  else
-    goto <bb 4>; [3.03%]
-
-  <bb 5> [local count: 1009658865]:
-  goto <bb 3>; [100.00%]
-
-  <bb 4> [local count: 32534376]:
-  # tmp_11 = PHI <tmp_7(3)>
-  return tmp_11;
+  tmp_11 = tmp_4(D) & bit2_6(D);
+  return tmp_11;

}

Ok for master ?

gcc/ChangeLog:

	PR middle-end/105735
	* match.pd (bitop_with_inv_p): New match.
	* tree-scalar-evolution.cc (gimple_bitop_with_inv_p): Declare.
	(analyze_and_compute_bitop_with_inv_effect): New function.
	(final_value_replacement_loop): Enhanced to handle bitop
	with inv induction.

gcc/testsuite/ChangeLog:

	* gcc.target/i386/pr105735-1.c: New test.
	* gcc.target/i386/pr105735-2.c: New test.
---
 gcc/match.pd                               |  4 +
 gcc/testsuite/gcc.target/i386/pr105735-1.c | 88 ++++++++++++++++++++++  gcc/testsuite/gcc.target/i386/pr105735-2.c | 28 +++++++
 gcc/tree-scalar-evolution.cc               | 59 +++++++++++++++
 4 files changed, 179 insertions(+)
 create mode 100644 gcc/testsuite/gcc.target/i386/pr105735-1.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr105735-2.c

diff --git a/gcc/match.pd b/gcc/match.pd index 562138a8034..cfe593ebb02 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -8050,6 +8050,10 @@ and,
  (bit_not
   (nop_convert1? (bit_xor@0 (convert2? (lshift integer_onep@1 @2)) @3))))
 
+(for bit_op (bit_and bit_ior bit_xor)
+ (match (bitop_with_inv_p @0 @1)
+  (bit_op:c @0 @1)))
+
 /* n - (((n > C1) ? n : C1) & -C2) ->  n & C1 for unsigned case.
    n - (((n > C1) ? n : C1) & -C2) ->  (n <= C1) ? n : (n & C1) for signed case.  */  (simplify diff --git a/gcc/testsuite/gcc.target/i386/pr105735-1.c b/gcc/testsuite/gcc.target/i386/pr105735-1.c
new file mode 100644
index 00000000000..8d2123ed351
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr105735-1.c
@@ -0,0 +1,88 @@
+/* { dg-do compile } */
+/* { dg-options "-O1 -fdump-tree-sccp-details" } */
+/* { dg-final { scan-tree-dump-times {final value replacement} 8 "sccp" 
+} } */
+
+unsigned long long
+__attribute__((noipa))
+foo (unsigned long long tmp, unsigned long long bit2) {
+  for (int bit = 0; bit < 64; bit++)
+    tmp &= bit2;
+  return tmp;
+}
+
+unsigned long long
+__attribute__((noipa))
+foo1 (unsigned long long tmp, unsigned long long bit2) {
+  for (int bit = 63; bit >= 0; bit -=3)
+    tmp &= bit2;
+  return tmp;
+}
+
+unsigned long long
+__attribute__((noipa))
+foo2 (unsigned long long tmp, unsigned long long bit2) {
+  for (int bit = 0; bit < 64; bit++)
+    tmp |= bit2;
+  return tmp;
+}
+
+unsigned long long
+__attribute__((noipa))
+foo3 (unsigned long long tmp, unsigned long long bit2) {
+  for (int bit = 63; bit >= 0; bit -=3)
+    tmp |= bit2;
+  return tmp;
+}
+
+unsigned long long
+__attribute__((noipa))
+foo4 (unsigned long long tmp, unsigned long long bit2) {
+  for (int bit = 0; bit < 64; bit++)
+    tmp ^= bit2;
+  return tmp;
+}
+
+unsigned long long
+__attribute__((noipa))
+foo5 (unsigned long long tmp, unsigned long long bit2) {
+  for (int bit = 0; bit < 63; bit++)
+    tmp ^= bit2;
+  return tmp;
+}
+
+unsigned long long
+__attribute__((noipa))
+f (unsigned long long tmp, long long bit, unsigned long long bit2) {
+  unsigned long long res = tmp;
+  for (long long i = 0; i < bit; i++)
+    res &= bit2;
+  return res;
+}
+
+unsigned long long
+__attribute__((noipa))
+f1 (unsigned long long tmp, long long bit, unsigned long long bit2) {
+  unsigned long long res = tmp;
+  for (long long i = 0; i < bit; i++)
+    res |= bit2;
+  return res;
+}
+
+unsigned long long
+__attribute__((noipa))
+f2 (unsigned long long tmp, long long bit, unsigned long long bit2) {
+  unsigned long long res = tmp;
+  for (long long i = 0; i < bit; i++)
+    res ^= bit2;
+  return res;
+}
+
diff --git a/gcc/testsuite/gcc.target/i386/pr105735-2.c b/gcc/testsuite/gcc.target/i386/pr105735-2.c
new file mode 100644
index 00000000000..79c1d300b1b
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr105735-2.c
@@ -0,0 +1,28 @@
+/* { dg-do run } */
+/* { dg-options "-O1" } */
+
+#include "pr105735-1.c"
+
+int main()
+{
+  unsigned long long tmp = 0x1101101ULL;
+  unsigned long long bit2 = 0x1111111011110111ULL;
+  if (foo (tmp, bit2) != 0x1100101ULL)
+    __builtin_abort ();
+  if (foo1 (tmp, bit2) != 0x1100101ULL)
+    __builtin_abort ();
+  if (foo2 (tmp, bit2) != 0x1111111011111111ULL)
+    __builtin_abort ();
+  if (foo3 (tmp, bit2) != 0x1111111011111111ULL)
+    __builtin_abort ();
+  if (foo4 (tmp, bit2) != 0x1101101ULL)
+    __builtin_abort ();
+  if (foo5 (tmp, bit2) != 0x1111111010011010ULL)
+    __builtin_abort ();
+  if (f (tmp, 64, bit2) != 0x1100101ULL)
+    __builtin_abort ();
+  if (f1 (tmp, 64, bit2) != 0x1111111011111111ULL)
+    __builtin_abort ();
+  if (f2 (tmp, 64, bit2) != 0x1101101ULL)
+    __builtin_abort ();
+}
diff --git a/gcc/tree-scalar-evolution.cc b/gcc/tree-scalar-evolution.cc index fc59d035b19..81220f08d2e 100644
--- a/gcc/tree-scalar-evolution.cc
+++ b/gcc/tree-scalar-evolution.cc
@@ -3635,6 +3635,53 @@ enum bit_op_kind
   return fold_build2 (code1, type, inv, wide_int_to_tree (type, bits));  }
 
+/* Match.pd function to match bitop with invariant expression
+  .i.e.
+  tmp_7 = _0 & _1; */
+extern bool gimple_bitop_with_inv_p (tree, tree *, tree (*)(tree));
+
+/* Return the inductive expression of bitop with invariant if possible,
+   otherwise returns DEF.  */
+static tree
+analyze_and_compute_bitop_with_inv_effect (class loop* loop, tree phidef,
+					   tree niter)
+{
+  tree match_op[2],inv;
+  tree type = TREE_TYPE (phidef);
+  gphi* header_phi = NULL;
+  /* match thing like op0 (match[0]), op1(match[1]), phidef(PHIDEF)
+
+    op1 =  PHI <phidef, inv>
+    phidef = op0 & op1
+    if op0 is an invariant, it could change to
+    phidef = op0 & inv.  */
+  if (!gimple_bitop_with_inv_p (phidef, &match_op[0], NULL)
+      || TREE_CODE (match_op[1]) != SSA_NAME
+      || !expr_invariant_in_loop_p (loop, match_op[0])
+      || !(header_phi = dyn_cast <gphi *> (SSA_NAME_DEF_STMT (match_op[1])))
+      || gimple_phi_num_args (header_phi) != 2)
+    return NULL_TREE;
+
+  if (PHI_ARG_DEF_FROM_EDGE (header_phi, loop_latch_edge (loop)) != phidef)
+    return NULL_TREE;
+
+  enum tree_code code1
+    = gimple_assign_rhs_code (SSA_NAME_DEF_STMT (phidef));
+
+  if (code1 == BIT_XOR_EXPR)
+    {
+       if (!tree_fits_uhwi_p (niter))
+	return NULL_TREE;
+       unsigned HOST_WIDE_INT niter_num;
+       niter_num = tree_to_uhwi (niter);
+       if (niter_num % 2 != 0)
+	match_op[0] =  build_zero_cst (type);
+    }
+
+  inv = PHI_ARG_DEF_FROM_EDGE (header_phi, loop_preheader_edge (loop));
+  return fold_build2 (code1, type, inv, match_op[0]); }
+
 /* Do final value replacement for LOOP, return true if we did anything.  */
 
 bool
@@ -3687,6 +3734,18 @@ final_value_replacement_loop (class loop *loop)
 					      &folded_casts);
       def = compute_overall_effect_of_inner_loop (ex_loop, def);
 
+      /* Handle bitop with invariant induction expression.
+
+	.i.e
+	for (int i =0 ;i < 32; i++)
+	  tmp &= bit2;
+	if bit2 is an invariant in loop which could simple to
+	tmp &= bit2.  */
+      tree bitinv_def;
+      if ((bitinv_def
+	   = analyze_and_compute_bitop_with_inv_effect (loop, phidef, niter)))
+	def = bitinv_def;
+
       /* Handle bitwise induction expression.
 
 	 .i.e.
--
2.18.2