[PATCH, i386] Add *popcounthi2_1 insn and splitter

[Uros Bizjak]

Hello!

This patch just adds missing popcounthi2 insn and splitter to enable
POPCNTW generation from _builtin_popcount builtin with zero-extended
unsigned short argument.

2016-12-19  Uros Bizjak  <ubiz...@gmail.com>

    * config/i386/i386.md (*popcounthi2_1): New insn_and_split pattern.

testsuite/ChangeLog:

2016-12-19  Uros Bizjak  <ubiz...@gmail.com>

    * gcc.target/i386/pr59874-3.c: New test.

Bootstrapped and regression tested on x86_64-linux-gnu {,-m32}.

Committed to mainline SVN.

Uros.

Index: config/i386/i386.md
===================================================================
--- config/i386/i386.md (revision 243799)
+++ config/i386/i386.md (working copy)
@@ -13221,6 +13221,24 @@
    (set_attr "type" "bitmanip")
    (set_attr "mode" "<MODE>")])
 
+(define_insn_and_split "*popcounthi2_1"
+  [(set (match_operand:SI 0 "register_operand")
+       (popcount:SI
+         (zero_extend:SI (match_operand:HI 1 "nonimmediate_operand"))))
+   (clobber (reg:CC FLAGS_REG))]
+  "TARGET_POPCNT
+   && can_create_pseudo_p ()"
+  "#"
+  "&& 1"
+  [(const_int 0)]
+{
+  rtx tmp = gen_reg_rtx (HImode);
+
+  emit_insn (gen_popcounthi2 (tmp, operands[1]));
+  emit_insn (gen_zero_extendhisi2 (operands[0], tmp));
+  DONE;
+})
+
 (define_insn "popcounthi2"
   [(set (match_operand:HI 0 "register_operand" "=r")
        (popcount:HI
Index: testsuite/gcc.target/i386/pr59874-3.c
===================================================================
--- testsuite/gcc.target/i386/pr59874-3.c       (nonexistent)
+++ testsuite/gcc.target/i386/pr59874-3.c       (working copy)
@@ -0,0 +1,10 @@
+/* PR target/59874 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -mpopcnt -masm=att" } */
+/* { dg-final { scan-assembler "popcntw" } } */
+
+unsigned int
+foo (unsigned short x)
+{
+  return __builtin_popcount (x);
+}