[PATCHv7] sysdeps/ieee754: prevent maybe-uninitialized errors with -O [BZ #19444]

Message ID 20181217213223.25527-1-Martin.Jansa@gmail.com
State New, archived
Headers

Commit Message

Martin Jansa Dec. 17, 2018, 9:32 p.m. UTC
  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(+)
  

Comments

Joseph Myers Dec. 17, 2018, 9:49 p.m. UTC | #1
This patch is OK.
  
Martin Jansa Jan. 4, 2019, 1:23 a.m. UTC | #2
On Mon, Dec 17, 2018 at 09:49:16PM +0000, Joseph Myers wrote:
> This patch is OK.

Hi,

if it's ok, can you please merge it?

I'm also still waiting for review (or merge) of the other one from this
thread:

"locale: prevent maybe-uninitialized errors with -Os [BZ #19444]"

Thanks,
  
Joseph Myers Jan. 4, 2019, 4:19 p.m. UTC | #3
On Fri, 4 Jan 2019, Martin Jansa wrote:

> On Mon, Dec 17, 2018 at 09:49:16PM +0000, Joseph Myers wrote:
> > This patch is OK.
> 
> Hi,
> 
> if it's ok, can you please merge it?

Done.
  

Patch

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);
       }