From: Jeff Law <law@redhat.com>
Date: Mon, 21 Sep 2015 17:09:53 +0000 (-0600)
Subject: [PATCH] Fix undefined behavior in h8300 backend
X-Git-Tag: basepoints/gcc-7~4442
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d7b00a16de70d84dce94a1f760265497f3408a7b;p=thirdparty%2Fgcc.git

[PATCH] Fix undefined behavior in h8300 backend

	* config/h8300/h8300.md (andsi3_ashift_n_lower): Avoid undefined
	behavior.

	* gcc.target/h8300/andsi3_ashift_n_lower.c: New test.

From-SVN: r227978
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index c25888aa09bb..b6527de27b3a 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2015-09-21  Jeff Law  <law@redhat.com>
+
+	* config/h8300/h8300.md (andsi3_ashift_n_lower): Avoid undefined
+	behavior. 
+
 2015-09-21  Ulrich Weigand  <Ulrich.Weigand@de.ibm.com>
 
 	* config/spu/spu.c (spu_expand_insv): Avoid undefined behavior.
diff --git a/gcc/config/h8300/h8300.md b/gcc/config/h8300/h8300.md
index 4079b306d5cb..52213ace20f3 100644
--- a/gcc/config/h8300/h8300.md
+++ b/gcc/config/h8300/h8300.md
@@ -3914,7 +3914,8 @@
    (clobber (match_scratch:QI 4 "=X,&r"))]
   "(TARGET_H8300H || TARGET_H8300S)
     && INTVAL (operands[2]) <= 15
-    && INTVAL (operands[3]) == ((-1 << INTVAL (operands[2])) & 0xffff)"
+    && UINTVAL (operands[3]) == ((HOST_WIDE_INT_M1U << INTVAL (operands[2]))
+				 & 0xffff)"
   "#"
   "&& reload_completed"
   [(parallel [(set (match_dup 5)
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index c65469fef03b..7afd523d80af 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2015-09-21  Jeff Law  <law@redhat.com>
+
+	* gcc.target/h8300/andsi3_ashift_n_lower.c: New test.
+
 2015-09-21  Ville Voutilainen  <ville.voutilainen@gmail.com>
 
 	Complete the implementation of N4230, Nested namespace definition.
diff --git a/gcc/testsuite/gcc.target/h8300/andsi3_ashift_n_lower.c b/gcc/testsuite/gcc.target/h8300/andsi3_ashift_n_lower.c
new file mode 100644
index 000000000000..8cacc52a4094
--- /dev/null
+++ b/gcc/testsuite/gcc.target/h8300/andsi3_ashift_n_lower.c
@@ -0,0 +1,7 @@
+/* { dg-do compile }  */
+/* { dg-options "-mh -O2 -fomit-frame-pointer" }  */
+/* { dg-final { scan-assembler-times "extu" 1 } }  */
+
+unsigned long foo(unsigned long a)
+  { return (a << 4) & 0xffff; }
+