[PATCH] [pass_if_conversion] Extend is_cond_scalar_reduction to handle bit_and/bit_xor/bit_ior.

liuhongt hongtao.liu@intel.com
Tue Nov 9 02:09:40 GMT 2021


This will enable transformation like

-  # sum1_50 = PHI <prephitmp_64(13), 0(4)>
-  # sum2_52 = PHI <sum2_21(13), 0(4)>
+  # sum1_50 = PHI <_87(13), 0(4)>
+  # sum2_52 = PHI <_89(13), 0(4)>
   # ivtmp_62 = PHI <ivtmp_61(13), 64(4)>
   i.2_7 = (long unsigned int) i_49;
   _8 = i.2_7 * 8;
...
   vec1_i_38 = vec1_29 >> _10;
   vec2_i_39 = vec2_31 >> _10;
   _11 = vec1_i_38 & 1;
-  _63 = tmp_37 ^ sum1_50;
-  prephitmp_64 = _11 == 0 ? sum1_50 : _63;
+  _ifc__86 = _11 != 0 ? tmp_37 : 0;
+  _87 = sum1_50 ^ _ifc__86;
   _12 = vec2_i_39 & 1;
:

so that vectorizer won't failed due to

  /* If this isn't a nested cycle or if the nested cycle reduction value
     is used ouside of the inner loop we cannot handle uses of the reduction
     value.  */
  if (nlatch_def_loop_uses > 1 || nphi_def_loop_uses > 1)
    {
      if (dump_enabled_p ())
	dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
			 "reduction used in loop.\n");
      return NULL;
    }

Bootstrap and regtest on x86_64-pc-linux-gnu{-m32,}
Ok for trunk?

gcc/ChangeLog:

	PR tree-optimization/103126
	* tree-if-conv.c (is_cond_scalar_reduction): Handle
	BIT_XOR_EXPR/BIT_IOR_EXPR/BIT_AND_EXPR.
	(convert_scalar_cond_reduction): Ditto.

gcc/testsuite/ChangeLog:

	* gcc.target/i386/ifcvt-reduction-logic-op.c: New test.
---
 .../i386/ifcvt-reduction-logic-op.c           | 80 +++++++++++++++++++
 gcc/tree-if-conv.c                            | 19 +++--
 2 files changed, 92 insertions(+), 7 deletions(-)
 create mode 100644 gcc/testsuite/gcc.target/i386/ifcvt-reduction-logic-op.c

diff --git a/gcc/testsuite/gcc.target/i386/ifcvt-reduction-logic-op.c b/gcc/testsuite/gcc.target/i386/ifcvt-reduction-logic-op.c
new file mode 100644
index 00000000000..eeb822d5d43
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/ifcvt-reduction-logic-op.c
@@ -0,0 +1,80 @@
+/* PR tree-optimization/103126.  */
+/* { dg-do compile } */
+/* { dg-options "-Ofast -mavx2 -ftree-vectorize -fdump-tree-vect-details" } */
+/* { dg-final { scan-tree-dump-times "vectorized \[1-3] loops" 3 "vect" } } */
+#include<stdint.h>
+
+void xor_bit_arr_nolcd (uint64_t *__restrict mat, uint64_t* a,uint64_t* b, uint64_t *__restrict ans,
+    int64_t n)
+{
+  int64_t i;
+  uint64_t vec1, sum1;
+  uint64_t vec2, sum2;
+
+  while (n > 0) {
+    sum1 = 0;
+    vec1 = a[n];
+    sum2 = 0;
+    vec2 = b[n];
+
+    for (i = 0; i < 64; i++) {
+      uint64_t tmp = mat[i];
+      uint64_t vec1_i = (vec1 >> i);
+      uint64_t vec2_i = (vec2 >> i);
+      sum1 ^= (vec1_i & 1) ? tmp : 0;
+      if (vec2_i&1) sum2 ^= tmp;
+    }
+    *ans++ ^= sum1;  n--;
+    *ans++ ^= sum2;  n--;
+  }
+}
+
+void ior_bit_arr_nolcd (uint64_t *__restrict mat, uint64_t* a,uint64_t* b, uint64_t *__restrict ans,
+    int64_t n)
+{
+  int64_t i;
+  uint64_t vec1, sum1;
+  uint64_t vec2, sum2;
+
+  while (n > 0) {
+    sum1 = 0;
+    vec1 = a[n];
+    sum2 = 0;
+    vec2 = b[n];
+
+    for (i = 0; i < 64; i++) {
+      uint64_t tmp = mat[i];
+      uint64_t vec1_i = (vec1 >> i);
+      uint64_t vec2_i = (vec2 >> i);
+      sum1 |= (vec1_i & 1) ? tmp : 0;
+      if (vec2_i&1) sum2 |= tmp;
+    }
+    *ans++ |= sum1;  n--;
+    *ans++ |= sum2;  n--;
+  }
+}
+
+void and_bit_arr_nolcd (uint64_t *__restrict mat, uint64_t* a,uint64_t* b, uint64_t *__restrict ans,
+    int64_t n)
+{
+  int64_t i;
+  uint64_t vec1, sum1;
+  uint64_t vec2, sum2;
+
+  while (n > 0) {
+    sum1 = -1;
+    vec1 = a[n];
+    sum2 = 0;
+    vec2 = b[n];
+
+    for (i = 0; i < 64; i++) {
+      uint64_t tmp = mat[i];
+      uint64_t vec1_i = (vec1 >> i);
+      uint64_t vec2_i = (vec2 >> i);
+      sum1 &= (vec1_i & 1) ? tmp : -1;
+      if (vec2_i&1) sum2 &= tmp;
+    }
+    *ans++ &= sum1;  n--;
+    *ans++ &= sum2;  n--;
+  }
+}
diff --git a/gcc/tree-if-conv.c b/gcc/tree-if-conv.c
index b165dc0c17f..7df1103ff89 100644
--- a/gcc/tree-if-conv.c
+++ b/gcc/tree-if-conv.c
@@ -1732,7 +1732,9 @@ is_cond_scalar_reduction (gimple *phi, gimple **reduc, tree arg_0, tree arg_1,
       reduction_op = gimple_assign_rhs_code (stmt);
     }
 
-  if (reduction_op != PLUS_EXPR && reduction_op != MINUS_EXPR)
+  if (reduction_op != PLUS_EXPR && reduction_op != MINUS_EXPR
+     && reduction_op != BIT_IOR_EXPR && reduction_op != BIT_XOR_EXPR
+     && reduction_op != BIT_AND_EXPR)
     return false;
   r_op1 = gimple_assign_rhs1 (stmt);
   r_op2 = gimple_assign_rhs2 (stmt);
@@ -1742,7 +1744,7 @@ is_cond_scalar_reduction (gimple *phi, gimple **reduc, tree arg_0, tree arg_1,
 
   /* Make R_OP1 to hold reduction variable.  */
   if (r_nop2 == PHI_RESULT (header_phi)
-      && reduction_op == PLUS_EXPR)
+      && commutative_tree_code (reduction_op))
     {
       std::swap (r_op1, r_op2);
       std::swap (r_nop1, r_nop2);
@@ -1811,7 +1813,10 @@ convert_scalar_cond_reduction (gimple *reduc, gimple_stmt_iterator *gsi,
   tree rhs1 = gimple_assign_rhs1 (reduc);
   tree tmp = make_temp_ssa_name (TREE_TYPE (rhs1), NULL, "_ifc_");
   tree c;
-  tree zero = build_zero_cst (TREE_TYPE (rhs1));
+  enum tree_code reduction_op  = gimple_assign_rhs_code (reduc);
+  tree op_nochange = reduction_op != BIT_AND_EXPR
+    ? build_zero_cst (TREE_TYPE (rhs1))
+    : build_minus_one_cst (TREE_TYPE (rhs1));
   gimple_seq stmts = NULL;
 
   if (dump_file && (dump_flags & TDF_DETAILS))
@@ -1824,14 +1829,14 @@ convert_scalar_cond_reduction (gimple *reduc, gimple_stmt_iterator *gsi,
      of reduction rhs.  */
   c = fold_build_cond_expr (TREE_TYPE (rhs1),
 			    unshare_expr (cond),
-			    swap ? zero : op1,
-			    swap ? op1 : zero);
+			    swap ? op_nochange : op1,
+			    swap ? op1 : op_nochange);
 
   /* Create assignment stmt and insert it at GSI.  */
   new_assign = gimple_build_assign (tmp, c);
   gsi_insert_before (gsi, new_assign, GSI_SAME_STMT);
-  /* Build rhs for unconditional increment/decrement.  */
-  rhs = gimple_build (&stmts, gimple_assign_rhs_code (reduc),
+  /* Build rhs for unconditional increment/decrement/logic_operation.  */
+  rhs = gimple_build (&stmts, reduction_op,
 		      TREE_TYPE (rhs1), op0, tmp);
 
   if (has_nop)
-- 
2.18.1



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