| Message ID | mptedq7lai9.fsf@arm.com |
|---|---|
| State | New |
| Headers | show |
| Series | Avoid creating (const (reg ...)) [PR108603] | expand |
On Thu, Mar 2, 2023 at 11:21 AM Richard Sandiford via Gcc-patches <gcc-patches@gcc.gnu.org> wrote: > > convert_memory_address_addr_space_1 has two modes: one in which it > tries to create a self-contained RTL expression (which might fail) > and one in which it can emit new instructions where necessary. > > When handling a CONST, the function recurses into the CONST's > operand and then constifies the result. But that's only valid if > the result is still a self-contained expression. If new instructions > have been emitted, the expression will refer to the (non-constant) > results of those instructions. > > In the PR, this caused us to emit a nonsensical (const (reg ...)) > REG_EQUAL note. > > Tested on aarch64-linux-gnu & x86_64-linux-gnu. OK to install? OK. Thanks, Richard. > Richard > > > gcc/ > PR tree-optimization/108603 > * explow.cc (convert_memory_address_addr_space_1): Only wrap > the result of a recursive call in a CONST if no instructions > were emitted. > > gcc/testsuite/ > PR tree-optimization/108603 > * gcc.target/aarch64/sve/pr108603.c: New test. > --- > gcc/explow.cc | 11 ++++++++--- > gcc/testsuite/gcc.target/aarch64/sve/pr108603.c | 8 ++++++++ > 2 files changed, 16 insertions(+), 3 deletions(-) > create mode 100644 gcc/testsuite/gcc.target/aarch64/sve/pr108603.c > > diff --git a/gcc/explow.cc b/gcc/explow.cc > index 83439b32abe..32e9498ee07 100644 > --- a/gcc/explow.cc > +++ b/gcc/explow.cc > @@ -349,9 +349,14 @@ convert_memory_address_addr_space_1 (scalar_int_mode to_mode ATTRIBUTE_UNUSED, > return temp; > > case CONST: > - temp = convert_memory_address_addr_space_1 (to_mode, XEXP (x, 0), as, > - true, no_emit); > - return temp ? gen_rtx_CONST (to_mode, temp) : temp; > + { > + auto *last = no_emit ? nullptr : get_last_insn (); > + temp = convert_memory_address_addr_space_1 (to_mode, XEXP (x, 0), as, > + true, no_emit); > + if (temp && (no_emit || last == get_last_insn ())) > + return gen_rtx_CONST (to_mode, temp); > + return temp; > + } > > case PLUS: > case MULT: > diff --git a/gcc/testsuite/gcc.target/aarch64/sve/pr108603.c b/gcc/testsuite/gcc.target/aarch64/sve/pr108603.c > new file mode 100644 > index 00000000000..a2aea9f0b12 > --- /dev/null > +++ b/gcc/testsuite/gcc.target/aarch64/sve/pr108603.c > @@ -0,0 +1,8 @@ > +/* { dg-options "-O2 -mabi=ilp32 -fdata-sections" } */ > + > +int a[128]; > +long long *p; > +void f() { > + for (long i = 0; i < sizeof(long); i++) > + p[i] = a[i]; > +} > -- > 2.25.1 >
diff --git a/gcc/explow.cc b/gcc/explow.cc index 83439b32abe..32e9498ee07 100644 --- a/gcc/explow.cc +++ b/gcc/explow.cc @@ -349,9 +349,14 @@ convert_memory_address_addr_space_1 (scalar_int_mode to_mode ATTRIBUTE_UNUSED, return temp; case CONST: - temp = convert_memory_address_addr_space_1 (to_mode, XEXP (x, 0), as, - true, no_emit); - return temp ? gen_rtx_CONST (to_mode, temp) : temp; + { + auto *last = no_emit ? nullptr : get_last_insn (); + temp = convert_memory_address_addr_space_1 (to_mode, XEXP (x, 0), as, + true, no_emit); + if (temp && (no_emit || last == get_last_insn ())) + return gen_rtx_CONST (to_mode, temp); + return temp; + } case PLUS: case MULT: diff --git a/gcc/testsuite/gcc.target/aarch64/sve/pr108603.c b/gcc/testsuite/gcc.target/aarch64/sve/pr108603.c new file mode 100644 index 00000000000..a2aea9f0b12 --- /dev/null +++ b/gcc/testsuite/gcc.target/aarch64/sve/pr108603.c @@ -0,0 +1,8 @@ +/* { dg-options "-O2 -mabi=ilp32 -fdata-sections" } */ + +int a[128]; +long long *p; +void f() { + for (long i = 0; i < sizeof(long); i++) + p[i] = a[i]; +}