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| author | Andreas Krebbel <krebbel@linux.ibm.com> | 2024-03-14 09:54:31 +0100 |
|---|---|---|
| committer | Andreas Krebbel <krebbel@linux.ibm.com> | 2024-03-14 10:51:57 +0100 |
| commit | 90a7da695284da49182446ba45fbcddb9eb7fc91 (patch) | |
| tree | 6ba55dd468343a688561e0af94262a465f73ff08 /gcc/config/s390 | |
| parent | 8f6e0814b4bfd0a399055e9214562aebfcd902ad (diff) | |
| download | gcc-90a7da695284da49182446ba45fbcddb9eb7fc91.zip gcc-90a7da695284da49182446ba45fbcddb9eb7fc91.tar.gz gcc-90a7da695284da49182446ba45fbcddb9eb7fc91.tar.bz2 | |
IBM Z: Fix -munaligned-symbols
With this fix we make sure that only symbols with a natural alignment
smaller than 2 are considered misaligned with
-munaligned-symbols. Background is that -munaligned-symbols is only
supposed to affect symbols whose natural alignment wouldn't be enough
to fulfill our ABI requirement of having all symbols at even
addresses. Because only these are the cases where we differ from other
architectures.
gcc/ChangeLog:
* config/s390/s390.cc (s390_encode_section_info): Adjust the check
for misaligned symbols.
* config/s390/s390.opt: Improve documentation.
gcc/testsuite/ChangeLog:
* gcc.target/s390/aligned-1.c: Add weak and void variables
incorporating the cases from unaligned-2.c.
* gcc.target/s390/unaligned-1.c: Likewise.
* gcc.target/s390/unaligned-2.c: Removed.
Diffstat (limited to 'gcc/config/s390')
| -rw-r--r-- | gcc/config/s390/s390.cc | 15 | ||||
| -rw-r--r-- | gcc/config/s390/s390.opt | 7 |
2 files changed, 16 insertions, 6 deletions
diff --git a/gcc/config/s390/s390.cc b/gcc/config/s390/s390.cc index e639655..372a232 100644 --- a/gcc/config/s390/s390.cc +++ b/gcc/config/s390/s390.cc @@ -13802,10 +13802,19 @@ s390_encode_section_info (tree decl, rtx rtl, int first) that can go wrong (i.e. no FUNC_DECLs). All symbols without an explicit alignment are assumed to be 2 byte aligned as mandated by our ABI. This behavior can be - overridden for external symbols with the -munaligned-symbols - switch. */ + overridden for external and weak symbols with the + -munaligned-symbols switch. + For all external symbols without explicit alignment + DECL_ALIGN is already trimmed down to 8, however for weak + symbols this does not happen. These cases are catched by the + type size check. */ + const_tree size = TYPE_SIZE (TREE_TYPE (decl)); + unsigned HOST_WIDE_INT size_num = (tree_fits_uhwi_p (size) + ? tree_to_uhwi (size) : 0); if ((DECL_USER_ALIGN (decl) && DECL_ALIGN (decl) % 16) - || (s390_unaligned_symbols_p && !decl_binds_to_current_def_p (decl))) + || (s390_unaligned_symbols_p + && !decl_binds_to_current_def_p (decl) + && (DECL_USER_ALIGN (decl) ? DECL_ALIGN (decl) % 16 : size_num < 16))) SYMBOL_FLAG_SET_NOTALIGN2 (XEXP (rtl, 0)); else if (DECL_ALIGN (decl) % 32) SYMBOL_FLAG_SET_NOTALIGN4 (XEXP (rtl, 0)); diff --git a/gcc/config/s390/s390.opt b/gcc/config/s390/s390.opt index 901ae4b..a5b5aa9 100644 --- a/gcc/config/s390/s390.opt +++ b/gcc/config/s390/s390.opt @@ -332,7 +332,8 @@ Store all argument registers on the stack. munaligned-symbols Target Var(s390_unaligned_symbols_p) Init(0) -Assume external symbols to be potentially unaligned. By default all -symbols without explicit alignment are assumed to reside on a 2 byte -boundary as mandated by the IBM Z ABI. +Assume external symbols, whose natural alignment would be 1, to be +potentially unaligned. By default all symbols without explicit +alignment are assumed to reside on a 2 byte boundary as mandated by +the IBM Z ABI. |