| From 546b46c309a52ed74dc906114b1e984bb9703d74 Mon Sep 17 00:00:00 2001 |
| From: Martin Jansa <Martin.Jansa@gmail.com> |
| Date: Fri, 14 Sep 2018 23:23:03 +0000 |
| Subject: [PATCH] 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 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. |
| |
| [BZ #23716] |
| * 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. |
| |
| Work around the issue instead of removing -O like we do with |
| SELECTED_OPTIMIZATION |
| |
| Upstream-Status: Submitted [https://www.sourceware.org/ml/libc-alpha/2018-09/msg00299.html] |
| |
| Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com> |
| --- |
| ChangeLog | 7 +++++++ |
| sysdeps/ieee754/dbl-64/e_jn.c | 21 +++++++++++++++++++++ |
| sysdeps/ieee754/ldbl-128/e_jnl.c | 21 +++++++++++++++++++++ |
| sysdeps/ieee754/ldbl-128ibm/e_jnl.c | 21 +++++++++++++++++++++ |
| sysdeps/ieee754/ldbl-96/e_jnl.c | 21 +++++++++++++++++++++ |
| 5 files changed, 91 insertions(+) |
| |
| diff --git a/ChangeLog b/ChangeLog |
| index 11a9b8d98e..922e916f2c 100644 |
| --- a/ChangeLog |
| +++ b/ChangeLog |
| @@ -1,3 +1,10 @@ |
| +2018-09-29 Martin Jansa <Martin.Jansa@gmail.com> |
| + Partial fix for [BZ #23716] |
| + * 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. |
| + |
| 2018-09-28 Adhemerval Zanella <adhemerval.zanella@linaro.org> |
| |
| [BZ #23579] |
| diff --git a/sysdeps/ieee754/dbl-64/e_jn.c b/sysdeps/ieee754/dbl-64/e_jn.c |
| index 9181b22bb8..9ff52c737f 100644 |
| --- a/sysdeps/ieee754/dbl-64/e_jn.c |
| +++ b/sysdeps/ieee754/dbl-64/e_jn.c |
| @@ -42,6 +42,7 @@ |
| #include <math-narrow-eval.h> |
| #include <math_private.h> |
| #include <math-underflow.h> |
| +#include <libc-diag.h> |
| |
| static const double |
| invsqrtpi = 5.64189583547756279280e-01, /* 0x3FE20DD7, 0x50429B6D */ |
| @@ -109,7 +110,17 @@ __ieee754_jn (int n, double x) |
| case 2: temp = -c - s; break; |
| case 3: temp = c - s; break; |
| } |
| + /* With GCC 8 (and older) when compiling with -O the compiler |
| + warns that the variable 'temp', may be used uninitialized. |
| + The switch above covers all possible values of n & 3 |
| + but GCC without VRP enabled isn't able to figure out the |
| + range of possible values is [0,3] as explained in: |
| + https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69230 |
| + so it's false possitive with -O1 and lower. */ |
| + DIAG_PUSH_NEEDS_COMMENT; |
| + DIAG_IGNORE_NEEDS_COMMENT (8, "-Wmaybe-uninitialized"); |
| b = invsqrtpi * temp / sqrt (x); |
| + DIAG_POP_NEEDS_COMMENT; |
| } |
| else |
| { |
| @@ -316,7 +327,17 @@ __ieee754_yn (int n, double x) |
| case 2: temp = -s + c; break; |
| case 3: temp = s + c; break; |
| } |
| + /* With GCC 8 (and older) when compiling with -O the compiler |
| + warns that the variable 'temp', may be used uninitialized. |
| + The switch above covers all possible values of n & 3 |
| + but GCC without VRP enabled isn't able to figure out the |
| + range of possible values is [0,3] as explained in: |
| + https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69230 |
| + so it's false possitive with -O1 and lower. */ |
| + DIAG_PUSH_NEEDS_COMMENT; |
| + DIAG_IGNORE_NEEDS_COMMENT (8, "-Wmaybe-uninitialized"); |
| b = invsqrtpi * temp / sqrt (x); |
| + DIAG_POP_NEEDS_COMMENT; |
| } |
| else |
| { |
| diff --git a/sysdeps/ieee754/ldbl-128/e_jnl.c b/sysdeps/ieee754/ldbl-128/e_jnl.c |
| index 7739eec291..8706a11575 100644 |
| --- a/sysdeps/ieee754/ldbl-128/e_jnl.c |
| +++ b/sysdeps/ieee754/ldbl-128/e_jnl.c |
| @@ -61,6 +61,7 @@ |
| #include <math.h> |
| #include <math_private.h> |
| #include <math-underflow.h> |
| +#include <libc-diag.h> |
| |
| static const _Float128 |
| invsqrtpi = L(5.6418958354775628694807945156077258584405E-1), |
| @@ -150,7 +151,17 @@ __ieee754_jnl (int n, _Float128 x) |
| temp = c - s; |
| break; |
| } |
| + /* With GCC 8 (and older) when compiling with -O the compiler |
| + warns that the variable 'temp', may be used uninitialized. |
| + The switch above covers all possible values of n & 3 |
| + but GCC without VRP enabled isn't able to figure out the |
| + range of possible values is [0,3] as explained in: |
| + https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69230 |
| + so it's false possitive with -O1 and lower. */ |
| + DIAG_PUSH_NEEDS_COMMENT; |
| + DIAG_IGNORE_NEEDS_COMMENT (8, "-Wmaybe-uninitialized"); |
| b = invsqrtpi * temp / sqrtl (x); |
| + DIAG_POP_NEEDS_COMMENT; |
| } |
| else |
| { |
| @@ -386,7 +397,17 @@ __ieee754_ynl (int n, _Float128 x) |
| temp = s + c; |
| break; |
| } |
| + /* With GCC 8 (and older) when compiling with -O the compiler |
| + warns that the variable 'temp', may be used uninitialized. |
| + The switch above covers all possible values of n & 3 |
| + but GCC without VRP enabled isn't able to figure out the |
| + range of possible values is [0,3] as explained in: |
| + https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69230 |
| + so it's false possitive with -O1 and lower. */ |
| + DIAG_PUSH_NEEDS_COMMENT; |
| + DIAG_IGNORE_NEEDS_COMMENT (8, "-Wmaybe-uninitialized"); |
| b = invsqrtpi * temp / sqrtl (x); |
| + DIAG_POP_NEEDS_COMMENT; |
| } |
| else |
| { |
| diff --git a/sysdeps/ieee754/ldbl-128ibm/e_jnl.c b/sysdeps/ieee754/ldbl-128ibm/e_jnl.c |
| index 71b3addfba..3226d02309 100644 |
| --- a/sysdeps/ieee754/ldbl-128ibm/e_jnl.c |
| +++ b/sysdeps/ieee754/ldbl-128ibm/e_jnl.c |
| @@ -61,6 +61,7 @@ |
| #include <math.h> |
| #include <math_private.h> |
| #include <math-underflow.h> |
| +#include <libc-diag.h> |
| |
| static const long double |
| invsqrtpi = 5.6418958354775628694807945156077258584405E-1L, |
| @@ -150,7 +151,17 @@ __ieee754_jnl (int n, long double x) |
| temp = c - s; |
| break; |
| } |
| + /* With GCC 8 (and older) when compiling with -O the compiler |
| + warns that the variable 'temp', may be used uninitialized. |
| + The switch above covers all possible values of n & 3 |
| + but GCC without VRP enabled isn't able to figure out the |
| + range of possible values is [0,3] as explained in: |
| + https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69230 |
| + so it's false possitive with -O1 and lower. */ |
| + DIAG_PUSH_NEEDS_COMMENT; |
| + DIAG_IGNORE_NEEDS_COMMENT (8, "-Wmaybe-uninitialized"); |
| b = invsqrtpi * temp / sqrtl (x); |
| + DIAG_POP_NEEDS_COMMENT; |
| } |
| else |
| { |
| @@ -386,7 +397,17 @@ __ieee754_ynl (int n, long double x) |
| temp = s + c; |
| break; |
| } |
| + /* With GCC 8 (and older) when compiling with -O the compiler |
| + warns that the variable 'temp', may be used uninitialized. |
| + The switch above covers all possible values of n & 3 |
| + but GCC without VRP enabled isn't able to figure out the |
| + range of possible values is [0,3] as explained in: |
| + https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69230 |
| + so it's false possitive with -O1 and lower. */ |
| + DIAG_PUSH_NEEDS_COMMENT; |
| + DIAG_IGNORE_NEEDS_COMMENT (8, "-Wmaybe-uninitialized"); |
| b = invsqrtpi * temp / sqrtl (x); |
| + DIAG_POP_NEEDS_COMMENT; |
| } |
| else |
| { |
| diff --git a/sysdeps/ieee754/ldbl-96/e_jnl.c b/sysdeps/ieee754/ldbl-96/e_jnl.c |
| index 394921f564..da5c2cc93e 100644 |
| --- a/sysdeps/ieee754/ldbl-96/e_jnl.c |
| +++ b/sysdeps/ieee754/ldbl-96/e_jnl.c |
| @@ -61,6 +61,7 @@ |
| #include <math.h> |
| #include <math_private.h> |
| #include <math-underflow.h> |
| +#include <libc-diag.h> |
| |
| static const long double |
| invsqrtpi = 5.64189583547756286948079e-1L, two = 2.0e0L, one = 1.0e0L; |
| @@ -143,7 +144,17 @@ __ieee754_jnl (int n, long double x) |
| temp = c - s; |
| break; |
| } |
| + /* With GCC 8 (and older) when compiling with -O the compiler |
| + warns that the variable 'temp', may be used uninitialized. |
| + The switch above covers all possible values of n & 3 |
| + but GCC without VRP enabled isn't able to figure out the |
| + range of possible values is [0,3] as explained in: |
| + https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69230 |
| + so it's false possitive with -O1 and lower. */ |
| + DIAG_PUSH_NEEDS_COMMENT; |
| + DIAG_IGNORE_NEEDS_COMMENT (8, "-Wmaybe-uninitialized"); |
| b = invsqrtpi * temp / sqrtl (x); |
| + DIAG_POP_NEEDS_COMMENT; |
| } |
| else |
| { |
| @@ -372,7 +383,17 @@ __ieee754_ynl (int n, long double x) |
| temp = s + c; |
| break; |
| } |
| + /* With GCC 8 (and older) when compiling with -O the compiler |
| + warns that the variable 'temp', may be used uninitialized. |
| + The switch above covers all possible values of n & 3 |
| + but GCC without VRP enabled isn't able to figure out the |
| + range of possible values is [0,3] as explained in: |
| + https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69230 |
| + so it's false possitive with -O1 and lower. */ |
| + DIAG_PUSH_NEEDS_COMMENT; |
| + DIAG_IGNORE_NEEDS_COMMENT (8, "-Wmaybe-uninitialized"); |
| b = invsqrtpi * temp / sqrtl (x); |
| + DIAG_POP_NEEDS_COMMENT; |
| } |
| else |
| { |