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[PATCHv7] sysdeps/ieee754: prevent maybe-uninitialized errors with -O [BZ #19444]
- From: Martin Jansa <martin dot jansa at gmail dot com>
- To: libc-alpha at sourceware dot org
- Cc: schwab at suse dot de, joseph at codesourcery dot com, Martin Jansa <Martin dot Jansa at gmail dot com>
- Date: Mon, 17 Dec 2018 21:32:23 +0000
- Subject: [PATCHv7] sysdeps/ieee754: prevent maybe-uninitialized errors with -O [BZ #19444]
- References: <alpine.DEB.2.21.1812172053590.9554@digraph.polyomino.org.uk>
With -O included in CFLAGS it fails to build with:
../sysdeps/ieee754/ldbl-96/e_jnl.c: In function '__ieee754_jnl':
../sysdeps/ieee754/ldbl-96/e_jnl.c:146:20: error: 'temp' may be used uninitialized in this function [-Werror=maybe-uninitialized]
b = invsqrtpi * temp / sqrtl (x);
~~~~~~~~~~^~~~~~
../sysdeps/ieee754/ldbl-96/e_jnl.c: In function '__ieee754_ynl':
../sysdeps/ieee754/ldbl-96/e_jnl.c:375:16: error: 'temp' may be used uninitialized in this function [-Werror=maybe-uninitialized]
b = invsqrtpi * temp / sqrtl (x);
~~~~~~~~~~^~~~~~
../sysdeps/ieee754/dbl-64/e_jn.c: In function '__ieee754_jn':
../sysdeps/ieee754/dbl-64/e_jn.c:113:20: error: 'temp' may be used uninitialized in this function [-Werror=maybe-uninitialized]
b = invsqrtpi * temp / sqrt (x);
~~~~~~~~~~^~~~~~
../sysdeps/ieee754/dbl-64/e_jn.c: In function '__ieee754_yn':
../sysdeps/ieee754/dbl-64/e_jn.c:320:16: error: 'temp' may be used uninitialized in this function [-Werror=maybe-uninitialized]
b = invsqrtpi * temp / sqrt (x);
~~~~~~~~~~^~~~~~
Build tested with Yocto for ARM, AARCH64, X86, X86_64, PPC, MIPS, MIPS64
with -O, -O1, -Os.
For soft-fp ARM it needs one more fix for -O1:
https://sourceware.org/ml/libc-alpha/2018-09/msg00300.html
For AARCH64 it needs one more fix in locale for -Os:
https://sourceware.org/ml/libc-alpha/2018-09/msg00539.html
[BZ #19444]
* sysdeps/ieee754/dbl-96/e_jnl.c: Fix build with -O
* sysdeps/ieee754/ldbl-96/e_jnl.c: Likewise.
* sysdeps/ieee754/ldbl-128/e_jnl.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/e_jnl.c: Likewise.
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
---
ChangeLog | 8 ++++++++
sysdeps/ieee754/dbl-64/e_jn.c | 2 ++
sysdeps/ieee754/ldbl-128/e_jnl.c | 4 ++++
sysdeps/ieee754/ldbl-128ibm/e_jnl.c | 4 ++++
sysdeps/ieee754/ldbl-96/e_jnl.c | 4 ++++
5 files changed, 22 insertions(+)
diff --git a/ChangeLog b/ChangeLog
index 99339f4605..2e12129846 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2018-12-17 Martin Jansa <Martin.Jansa@gmail.com>
+
+ Partial fix for [BZ #19444]
+ * sysdeps/ieee754/dbl-96/e_jnl.c: Fix build with -O
+ * sysdeps/ieee754/ldbl-96/e_jnl.c: Likewise.
+ * sysdeps/ieee754/ldbl-128/e_jnl.c: Likewise.
+ * sysdeps/ieee754/ldbl-128ibm/e_jnl.c: Likewise.
+
2018-12-17 Mao Han <han_mao@c-sky.com>
* sysdeps/unix/sysv/linux/Makefile: Add statx_cp.c.
diff --git a/sysdeps/ieee754/dbl-64/e_jn.c b/sysdeps/ieee754/dbl-64/e_jn.c
index aff06ead16..90a7e77270 100644
--- a/sysdeps/ieee754/dbl-64/e_jn.c
+++ b/sysdeps/ieee754/dbl-64/e_jn.c
@@ -109,6 +109,7 @@ __ieee754_jn (int n, double x)
case 1: temp = -c + s; break;
case 2: temp = -c - s; break;
case 3: temp = c - s; break;
+ default: __builtin_unreachable ();
}
b = invsqrtpi * temp / sqrt (x);
}
@@ -316,6 +317,7 @@ __ieee754_yn (int n, double x)
case 1: temp = -s - c; break;
case 2: temp = -s + c; break;
case 3: temp = s + c; break;
+ default: __builtin_unreachable ();
}
b = invsqrtpi * temp / sqrt (x);
}
diff --git a/sysdeps/ieee754/ldbl-128/e_jnl.c b/sysdeps/ieee754/ldbl-128/e_jnl.c
index 7610d18c67..3c90072a22 100644
--- a/sysdeps/ieee754/ldbl-128/e_jnl.c
+++ b/sysdeps/ieee754/ldbl-128/e_jnl.c
@@ -150,6 +150,8 @@ __ieee754_jnl (int n, _Float128 x)
case 3:
temp = c - s;
break;
+ default:
+ __builtin_unreachable ();
}
b = invsqrtpi * temp / sqrtl (x);
}
@@ -386,6 +388,8 @@ __ieee754_ynl (int n, _Float128 x)
case 3:
temp = s + c;
break;
+ default:
+ __builtin_unreachable ();
}
b = invsqrtpi * temp / sqrtl (x);
}
diff --git a/sysdeps/ieee754/ldbl-128ibm/e_jnl.c b/sysdeps/ieee754/ldbl-128ibm/e_jnl.c
index 50b4558e74..478824c8fa 100644
--- a/sysdeps/ieee754/ldbl-128ibm/e_jnl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/e_jnl.c
@@ -150,6 +150,8 @@ __ieee754_jnl (int n, long double x)
case 3:
temp = c - s;
break;
+ default:
+ __builtin_unreachable ();
}
b = invsqrtpi * temp / sqrtl (x);
}
@@ -386,6 +388,8 @@ __ieee754_ynl (int n, long double x)
case 3:
temp = s + c;
break;
+ default:
+ __builtin_unreachable ();
}
b = invsqrtpi * temp / sqrtl (x);
}
diff --git a/sysdeps/ieee754/ldbl-96/e_jnl.c b/sysdeps/ieee754/ldbl-96/e_jnl.c
index 855190841b..6c1c4b4653 100644
--- a/sysdeps/ieee754/ldbl-96/e_jnl.c
+++ b/sysdeps/ieee754/ldbl-96/e_jnl.c
@@ -143,6 +143,8 @@ __ieee754_jnl (int n, long double x)
case 3:
temp = c - s;
break;
+ default:
+ __builtin_unreachable ();
}
b = invsqrtpi * temp / sqrtl (x);
}
@@ -372,6 +374,8 @@ __ieee754_ynl (int n, long double x)
case 3:
temp = s + c;
break;
+ default:
+ __builtin_unreachable ();
}
b = invsqrtpi * temp / sqrtl (x);
}
--
2.17.1