From a4f2895465da4c8856b119a5787b95db345567a9 Mon Sep 17 00:00:00 2001
From: Martin Liska <mliska@suse.cz>
Date: Fri, 2 Dec 2016 09:36:01 +0100
Subject: Fix runtime error: left shift of negative value (PR

	PR ipa/78555
	* sreal.c (sreal::to_int): Make absolute value before shifting.
	(sreal::operator/): Likewise.
	(sreal_verify_negative_division): New test.
	(void sreal_c_tests): Call the new test.
	* sreal.h (sreal::normalize_up): Use new SREAL_ABS and
	SREAL_SIGN macros.
	(sreal::normalize_down): Likewise.

From-SVN: r243163
---
 gcc/sreal.h | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

(limited to 'gcc/sreal.h')

diff --git a/gcc/sreal.h b/gcc/sreal.h
index ce9cdbb..21f14b0 100644
--- a/gcc/sreal.h
+++ b/gcc/sreal.h
@@ -31,6 +31,9 @@ along with GCC; see the file COPYING3.  If not see
 
 #define SREAL_BITS SREAL_PART_BITS
 
+#define SREAL_SIGN(v) (v < 0 ? -1: 1)
+#define SREAL_ABS(v) (v < 0 ? -v: v)
+
 /* Structure for holding a simple real number.  */
 class sreal
 {
@@ -193,7 +196,6 @@ inline sreal operator>> (const sreal &a, int exp)
 inline void
 sreal::normalize_up ()
 {
-  int64_t s = m_sig < 0 ? -1 : 1;
   unsigned HOST_WIDE_INT sig = absu_hwi (m_sig);
   int shift = SREAL_PART_BITS - 2 - floor_log2 (sig);
 
@@ -208,7 +210,7 @@ sreal::normalize_up ()
       m_exp = -SREAL_MAX_EXP;
       sig = 0;
     }
-  if (s == -1)
+  if (SREAL_SIGN (m_sig) == -1)
     m_sig = -sig;
   else
     m_sig = sig;
@@ -221,7 +223,6 @@ sreal::normalize_up ()
 inline void
 sreal::normalize_down ()
 {
-  int64_t s = m_sig < 0 ? -1 : 1;
   int last_bit;
   unsigned HOST_WIDE_INT sig = absu_hwi (m_sig);
   int shift = floor_log2 (sig) - SREAL_PART_BITS + 2;
@@ -246,7 +247,7 @@ sreal::normalize_down ()
       m_exp = SREAL_MAX_EXP;
       sig = SREAL_MAX_SIG;
     }
-  if (s == -1)
+  if (SREAL_SIGN (m_sig) == -1)
     m_sig = -sig;
   else
     m_sig = sig;
-- 
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