From b06335f93e9bf0ba865ee3133032648b4d3ca223 Mon Sep 17 00:00:00 2001
From: Kyrylo Tkachov <kyrylo.tkachov@arm.com>
Date: Thu, 1 Sep 2016 09:03:52 +0000
Subject: [PATCH] [AArch64] Add ANDS pattern for CMP+ZERO_EXTEND

	* config/aarch64/aarch64.md (*ands<mode>_compare0): New pattern.
	* config/aarch64/aarch64.c (aarch64_select_cc_mode): Return CC_NZmode
	for comparisons of integer ZERO_EXTEND against zero.

	* gcc.target/aarch64/ands_3.c: New test.

From-SVN: r239919
---
 gcc/ChangeLog                             |  6 ++++++
 gcc/config/aarch64/aarch64.c              |  8 ++++++++
 gcc/config/aarch64/aarch64.md             | 12 ++++++++++++
 gcc/testsuite/ChangeLog                   |  4 ++++
 gcc/testsuite/gcc.target/aarch64/ands_3.c | 12 ++++++++++++
 5 files changed, 42 insertions(+)
 create mode 100644 gcc/testsuite/gcc.target/aarch64/ands_3.c

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 9f90359170e..bf5c54901e7 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2016-09-01  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
+	* config/aarch64/aarch64.md (*ands<mode>_compare0): New pattern.
+	* config/aarch64/aarch64.c (aarch64_select_cc_mode): Return CC_NZmode
+	for comparisons of integer ZERO_EXTEND against zero.
+
 2016-09-01  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* config/i386/i386.c (ix86_option_override_internal): Also disable the
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 3e663eb5f13..e813d66b40a 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -4264,6 +4264,14 @@ aarch64_select_cc_mode (RTX_CODE code, rtx x, rtx y)
       && (GET_MODE (x) == HImode || GET_MODE (x) == QImode))
     return CC_NZmode;
 
+  /* Similarly, comparisons of zero_extends from shorter modes can
+     be performed using an ANDS with an immediate mask.  */
+  if (y == const0_rtx && GET_CODE (x) == ZERO_EXTEND
+      && (GET_MODE (x) == SImode || GET_MODE (x) == DImode)
+      && (GET_MODE (XEXP (x, 0)) == HImode || GET_MODE (XEXP (x, 0)) == QImode)
+      && (code == EQ || code == NE))
+    return CC_NZmode;
+
   if ((GET_MODE (x) == SImode || GET_MODE (x) == DImode)
       && y == const0_rtx
       && (code == EQ || code == NE || code == LT || code == GE)
diff --git a/gcc/config/aarch64/aarch64.md b/gcc/config/aarch64/aarch64.md
index c95258b7103..6afaf906915 100644
--- a/gcc/config/aarch64/aarch64.md
+++ b/gcc/config/aarch64/aarch64.md
@@ -3811,6 +3811,18 @@
   [(set_attr "type" "alus_imm")]
 )
 
+(define_insn "*ands<mode>_compare0"
+  [(set (reg:CC_NZ CC_REGNUM)
+	(compare:CC_NZ
+	 (zero_extend:GPI (match_operand:SHORT 1 "register_operand" "r"))
+	 (const_int 0)))
+   (set (match_operand:GPI 0 "register_operand" "=r")
+	(zero_extend:GPI (match_dup 1)))]
+  ""
+  "ands\\t%<GPI:w>0, %<GPI:w>1, <short_mask>"
+  [(set_attr "type" "alus_imm")]
+)
+
 (define_insn "*and<mode>3nr_compare0"
   [(set (reg:CC_NZ CC_REGNUM)
 	(compare:CC_NZ
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 864215d9dc4..82f3daaa9f5 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2016-09-01  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
+	* gcc.target/aarch64/ands_3.c: New test.
+
 2016-08-31  Jakub Jelinek  <jakub@redhat.com>
 
 	PR fortran/77352
diff --git a/gcc/testsuite/gcc.target/aarch64/ands_3.c b/gcc/testsuite/gcc.target/aarch64/ands_3.c
new file mode 100644
index 00000000000..42cb7f0f0bc
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/ands_3.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+int
+f9 (unsigned char x, int y)
+{
+  if (y > 1 && x == 0)
+    return 10;
+  return x;
+}
+
+/* { dg-final { scan-assembler "ands\t(x|w)\[0-9\]+,\[ \t\]*(x|w)\[0-9\]+,\[ \t\]*255" } } */
-- 
2.30.2