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

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 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-64/e_jn.c (__ieee754_jn): Use
	__builtin_unreachable for default case in switch.
	(__ieee754_yn): Likewise.
	* sysdeps/ieee754/ldbl-96/e_jnl.c (__ieee754_jnl): Likewise.
	(__ieee754_ynl): Likewise.
	* sysdeps/ieee754/ldbl-128/e_jnl.c (__ieee754_jnl): Likewise.
	(__ieee754_ynl): Likewise.
	* sysdeps/ieee754/ldbl-128ibm/e_jnl.c (__ieee754_jnl): Likewise.
	(__ieee754_ynl): Likewise.

diff --git a/ChangeLog b/ChangeLog
index 811160d77a27807bb99df0bb02a55fa136286d55..a71c88fa4e559e91747e29647b21159af8575f02 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,16 @@
+2019-10-04  Martin Jansa  <Martin.Jansa@gmail.com>
+
+       [BZ #19444]
+       * sysdeps/ieee754/dbl-64/e_jn.c (__ieee754_jn): Use
+       __builtin_unreachable for default case in switch.
+       (__ieee754_yn): Likewise.
+       * sysdeps/ieee754/ldbl-96/e_jnl.c (__ieee754_jnl): Likewise.
+       (__ieee754_ynl): Likewise.
+       * sysdeps/ieee754/ldbl-128/e_jnl.c (__ieee754_jnl): Likewise.
+       (__ieee754_ynl): Likewise.
+       * sysdeps/ieee754/ldbl-128ibm/e_jnl.c (__ieee754_jnl): Likewise.
+       (__ieee754_ynl): Likewise.
+
 2019-01-04  Szabolcs Nagy  <szabolcs.nagy@arm.com>
 
        * manual/maint.texi: Use @{ and @}.

diff --git a/sysdeps/ieee754/dbl-64/e_jn.c b/sysdeps/ieee754/dbl-64/e_jn.c
index aff06ead1668d4e58e0662b706e9a2adc769dd28..90a7e772709491411f2722d314d2aaff85f48ca9 100644 (file)
--- 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 7610d18c67fd06dd625eb761594a78dc71451b41..3c90072a22b98ed7c4ef8fde7a06c8e0a27ea105 100644 (file)
--- 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 50b4558e747c97b2bbe91199e3d5f24fc47d8268..478824c8fad5964466ff0874e8b671d262b7225c 100644 (file)
--- 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 855190841b178df299eb4c1419a3c136a94dcc3e..6c1c4b4653eb6195dd0f762c868fd82e7f2b830f 100644 (file)
--- 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);
       }