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| author | Richard Biener <rguenther@suse.de> | 2017-04-25 12:15:44 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2017-04-25 12:15:44 +0000 |
| commit | bed3fd4637d24e27b61fbd7f366e98a211080a0b (patch) | |
| tree | 690cd4fd07d5f180a7f6871949ce641cfc7e1daf | |
| parent | ca0b6141fa6a9c98939224ebc3b7ddc171df5b96 (diff) | |
| download | gcc-bed3fd4637d24e27b61fbd7f366e98a211080a0b.zip gcc-bed3fd4637d24e27b61fbd7f366e98a211080a0b.tar.gz gcc-bed3fd4637d24e27b61fbd7f366e98a211080a0b.tar.bz2 | |
re PR tree-optimization/80492 (Wrong code when unrolling a loop with inline asm and local regs)
2017-04-25 Richard Biener <rguenther@suse.de>
PR tree-optimization/80492
* alias.c (compare_base_decls): Handle registers with asm
specification conservatively.
* tree-ssa-alias.c (decl_refs_may_alias_p): Handle
compare_base_decls returning dont-know properly.
* gcc.dg/pr80492.c: New testcase.
From-SVN: r247208
| -rw-r--r-- | gcc/ChangeLog | 8 | ||||
| -rw-r--r-- | gcc/alias.c | 12 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/pr80492.c | 20 | ||||
| -rw-r--r-- | gcc/tree-ssa-alias.c | 7 |
5 files changed, 50 insertions, 2 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 2f41647..4156779 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,11 @@ +2017-04-25 Richard Biener <rguenther@suse.de> + + PR tree-optimization/80492 + * alias.c (compare_base_decls): Handle registers with asm + specification conservatively. + * tree-ssa-alias.c (decl_refs_may_alias_p): Handle + compare_base_decls returning dont-know properly. + 2017-04-25 Claudiu Zissulescu <claziss@synopsys.com> * config/arc/arc.c (LEGITIMATE_OFFSET_ADDRESS_P): Delete macro. diff --git a/gcc/alias.c b/gcc/alias.c index efd89ce..e16e350 100644 --- a/gcc/alias.c +++ b/gcc/alias.c @@ -2046,6 +2046,18 @@ compare_base_decls (tree base1, tree base2) if (base1 == base2) return 1; + /* If we have two register decls with register specification we + cannot decide unless their assembler name is the same. */ + if (DECL_REGISTER (base1) + && DECL_REGISTER (base2) + && DECL_ASSEMBLER_NAME_SET_P (base1) + && DECL_ASSEMBLER_NAME_SET_P (base2)) + { + if (DECL_ASSEMBLER_NAME (base1) == DECL_ASSEMBLER_NAME (base2)) + return 1; + return -1; + } + /* Declarations of non-automatic variables may have aliases. All other decls are unique. */ if (!decl_in_symtab_p (base1) diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index fd6b9fa..576838e 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2017-04-25 Richard Biener <rguenther@suse.de> + + PR tree-optimization/80492 + * gcc.dg/pr80492.c: New testcase. + 2017-04-25 Senthil Kumar Selvaraj <senthil_kumar.selvaraj@atmel.com> * gcc.dg/attr-alloc_size-10.c: Ignore overflow warnings diff --git a/gcc/testsuite/gcc.dg/pr80492.c b/gcc/testsuite/gcc.dg/pr80492.c new file mode 100644 index 0000000..1721b2d --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr80492.c @@ -0,0 +1,20 @@ +/* { dg-do compile } */ +/* { dg-options "-w -O2 -fdump-tree-optimized" } */ + +static __inline__ __attribute__((__always_inline__)) +void syscall_7 (int val) +{ + register int reg __asm ("4") = val; + __asm __volatile__ ("/* Some Code %0 */" :: "r" (reg)); +} + +void do_syscalls (void) +{ + for (int s = 0; s < 2; s++) + { + syscall_7 (0); + syscall_7 (1); + } +} + +/* { dg-final { scan-tree-dump-times "reg = " 4 "optimized" } } */ diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c index 3f0c650..0dcb273 100644 --- a/gcc/tree-ssa-alias.c +++ b/gcc/tree-ssa-alias.c @@ -1096,13 +1096,16 @@ decl_refs_may_alias_p (tree ref1, tree base1, { gcc_checking_assert (DECL_P (base1) && DECL_P (base2)); + int cmp = compare_base_decls (base1, base2); + /* If both references are based on different variables, they cannot alias. */ - if (compare_base_decls (base1, base2) == 0) + if (cmp == 0) return false; /* If both references are based on the same variable, they cannot alias if the accesses do not overlap. */ - if (!ranges_overlap_p (offset1, max_size1, offset2, max_size2)) + if (cmp == 1 + && !ranges_overlap_p (offset1, max_size1, offset2, max_size2)) return false; /* For components with variable position, the above test isn't sufficient, |