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| author | Iain Buclaw <ibuclaw@gdcproject.org> | 2023-07-02 03:24:53 +0200 |
|---|---|---|
| committer | Iain Buclaw <ibuclaw@gdcproject.org> | 2023-07-02 03:37:05 +0200 |
| commit | 80ae426a195a0d035640a6301da833564deade52 (patch) | |
| tree | 0aa16cb1bc0df8e8c80db61da2aa46373ff2b0d4 | |
| parent | 67e0967b32af60cdf5a0c3e811bfa63c30dcdb76 (diff) | |
| download | gcc-80ae426a195a0d035640a6301da833564deade52.zip gcc-80ae426a195a0d035640a6301da833564deade52.tar.gz gcc-80ae426a195a0d035640a6301da833564deade52.tar.bz2 | |
d: Fix core.volatile.volatileLoad discarded if result is unused
The first pass of code generation in the D front-end splits up all
compound expressions and discards expressions that have no side effects.
This included calls to the `volatileLoad' intrinsic if its result was
not used, causing such calls to be eliminated from the program.
We already set TREE_THIS_VOLATILE on the expression, however the
tree documentation says if this bit is set in an expression, so is
TREE_SIDE_EFFECTS. So set TREE_SIDE_EFFECTS on the expression too.
This prevents any early discarding from occuring.
PR d/110516
gcc/d/ChangeLog:
* intrinsics.cc (expand_volatile_load): Set TREE_SIDE_EFFECTS on the
expanded expression.
(expand_volatile_store): Likewise.
gcc/testsuite/ChangeLog:
* gdc.dg/torture/pr110516a.d: New test.
* gdc.dg/torture/pr110516b.d: New test.
| -rw-r--r-- | gcc/d/intrinsics.cc | 2 | ||||
| -rw-r--r-- | gcc/testsuite/gdc.dg/torture/pr110516a.d | 12 | ||||
| -rw-r--r-- | gcc/testsuite/gdc.dg/torture/pr110516b.d | 12 |
3 files changed, 26 insertions, 0 deletions
diff --git a/gcc/d/intrinsics.cc b/gcc/d/intrinsics.cc index 0121d81..aaf04e5 100644 --- a/gcc/d/intrinsics.cc +++ b/gcc/d/intrinsics.cc @@ -1007,6 +1007,7 @@ expand_volatile_load (tree callexp) tree type = build_qualified_type (TREE_TYPE (ptrtype), TYPE_QUAL_VOLATILE); tree result = indirect_ref (type, ptr); TREE_THIS_VOLATILE (result) = 1; + TREE_SIDE_EFFECTS (result) = 1; return result; } @@ -1034,6 +1035,7 @@ expand_volatile_store (tree callexp) tree type = build_qualified_type (TREE_TYPE (ptrtype), TYPE_QUAL_VOLATILE); tree result = indirect_ref (type, ptr); TREE_THIS_VOLATILE (result) = 1; + TREE_SIDE_EFFECTS (result) = 1; /* (*(volatile T *) ptr) = value; */ tree value = CALL_EXPR_ARG (callexp, 1); diff --git a/gcc/testsuite/gdc.dg/torture/pr110516a.d b/gcc/testsuite/gdc.dg/torture/pr110516a.d new file mode 100644 index 0000000..276455a --- /dev/null +++ b/gcc/testsuite/gdc.dg/torture/pr110516a.d @@ -0,0 +1,12 @@ +// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110516 +// { dg-do compile } +// { dg-options "-fno-moduleinfo -fdump-tree-optimized" } +void fn110516(ubyte* ptr) +{ + import core.volatile : volatileLoad; + volatileLoad(ptr); + volatileLoad(ptr); + volatileLoad(ptr); + volatileLoad(ptr); +} +// { dg-final { scan-tree-dump-times " ={v} " 4 "optimized" } } diff --git a/gcc/testsuite/gdc.dg/torture/pr110516b.d b/gcc/testsuite/gdc.dg/torture/pr110516b.d new file mode 100644 index 0000000..b7a67e7 --- /dev/null +++ b/gcc/testsuite/gdc.dg/torture/pr110516b.d @@ -0,0 +1,12 @@ +// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110516 +// { dg-do compile } +// { dg-options "-fno-moduleinfo -fdump-tree-optimized" } +void fn110516(ubyte* ptr) +{ + import core.volatile : volatileStore; + volatileStore(ptr, 0); + volatileStore(ptr, 0); + volatileStore(ptr, 0); + volatileStore(ptr, 0); +} +// { dg-final { scan-tree-dump-times " ={v} " 4 "optimized" } } |