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author | Xavier Leroy <xavier.leroy@inria.fr> | 2015-07-08 11:42:39 +0200 |
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committer | Xavier Leroy <xavier.leroy@inria.fr> | 2015-07-08 11:42:39 +0200 |
commit | f869da75c970aec78975f7154c806f29e3012b7a (patch) | |
tree | 32bd1fc3fc05e51d7d339956b04196f80e0f2116 /test/regression | |
parent | 3eb2b3b7bb464d9844f7c161fbcff53f597348b9 (diff) | |
download | compcert-f869da75c970aec78975f7154c806f29e3012b7a.tar.gz compcert-f869da75c970aec78975f7154c806f29e3012b7a.zip |
Turn off copy optimization when returning a composite by reference.
The copy optimization is not correct in case of overlap between destination
and source. We would need to use an hypothetical __builtin_memmove_aligned
that can cope with overlap to implement the copy at return of callee.
Diffstat (limited to 'test/regression')
-rw-r--r-- | test/regression/Makefile | 2 | ||||
-rw-r--r-- | test/regression/Results/struct12 | 0 | ||||
-rw-r--r-- | test/regression/struct12.c | 39 |
3 files changed, 40 insertions, 1 deletions
diff --git a/test/regression/Makefile b/test/regression/Makefile index da7d5755..e2d94aa9 100644 --- a/test/regression/Makefile +++ b/test/regression/Makefile @@ -15,7 +15,7 @@ LIBS=$(LIBMATH) TESTS=int32 int64 floats floats-basics \ expr1 expr6 funptr2 initializers initializers2 initializers3 \ volatile1 volatile2 volatile3 \ - funct3 expr5 struct7 struct8 struct11 casts1 casts2 char1 \ + funct3 expr5 struct7 struct8 struct11 struct12 casts1 casts2 char1 \ sizeof1 sizeof2 binops bool for1 switch switch2 compound \ decl1 interop1 bitfields9 ptrs3 diff --git a/test/regression/Results/struct12 b/test/regression/Results/struct12 new file mode 100644 index 00000000..e69de29b --- /dev/null +++ b/test/regression/Results/struct12 diff --git a/test/regression/struct12.c b/test/regression/struct12.c new file mode 100644 index 00000000..39e62b28 --- /dev/null +++ b/test/regression/struct12.c @@ -0,0 +1,39 @@ +/* This is was originally a regression test for bug 43784 of gcc. + See ISO/IEC 9899:TC3 ยง6.8.6.4p4 and footnote 139. */ + +#include <stdio.h> + +struct s { + unsigned char a[256]; +}; +union u { + struct { struct s b; int c; } d; + struct { int c; struct s b; } e; +}; + +static union u v; +static struct s *p = &v.d.b; +static struct s *q = &v.e.b; + +static struct s __attribute__((noinline)) rp(void) +{ + return *p; +} + +static void qp(void) +{ + *q = rp(); +} + +int main() +{ + int i; + for (i = 0; i < 256; i++) + p->a[i] = i; + qp(); + for (i = 0; i < 256; i++) + if (q->a[i] != i) + printf("ERROR at %d: %d\n", i, q->a[i]); + return 0; +} + |