On Thu, Jul 25, 2024 at 3:23 PM Hongtao Liu <crazy...@gmail.com> wrote:
>
> On Wed, Jul 24, 2024 at 3:57 PM liuhongt <hongtao....@intel.com> wrote:
> >
> > For below pattern, RA may still allocate r162 as v/k register, try to
> > reload for address with leaq __libc_tsd_CTYPE_B@gottpoff(%rip), %rsi
> > which result a linker error.
> >
> > (set (reg:DI 162)
> > (mem/u/c:DI
> > (const:DI (unspec:DI
> > [(symbol_ref:DI ("a") [flags 0x60] <var_decl
> > 0x7f621f6e1c60 a>)]
> > UNSPEC_GOTNTPOFF))
> >
> > Quote from H.J for why linker issue an error.
> > >What do these do:
> > >
> > > leaq __libc_tsd_CTYPE_B@gottpoff(%rip), %rax
> > > vmovq (%rax), %xmm0
> > >
> > >From x86-64 TLS psABI:
> > >
> > >The assembler generates for the x@gottpoff(%rip) expressions a R X86
> > >64 GOTTPOFF relocation for the symbol x which requests the linker to
> > >generate a GOT entry with a R X86 64 TPOFF64 relocation. The offset of
> > >the GOT entry relative to the end of the instruction is then used in
> > >the instruction. The R X86 64 TPOFF64 relocation is pro- cessed at
> > >program startup time by the dynamic linker by looking up the symbol x
> > >in the modules loaded at that point. The offset is written in the GOT
> > >entry and later loaded by the addq instruction.
> > >
> > >The above code sequence looks wrong to me.
> >
> > Bootstrapped and regtested on x86_64-pc-linux-gnu{-m32,}.
> > Ok for trunk and backport?
Committed and will backport after gcc14.2 is released.
> >
> > gcc/ChangeLog:
> >
> > PR target/116043
> > * config/i386/constraints.md (Bk): Refine to
> > define_special_memory_constraint.
> >
> > gcc/testsuite/ChangeLog:
> >
> > * gcc.target/i386/pr116043.c: New test.
> > ---
> > gcc/config/i386/constraints.md | 2 +-
> > gcc/testsuite/gcc.target/i386/pr116043.c | 33 ++++++++++++++++++++++++
> > 2 files changed, 34 insertions(+), 1 deletion(-)
> > create mode 100644 gcc/testsuite/gcc.target/i386/pr116043.c
> >
> > diff --git a/gcc/config/i386/constraints.md b/gcc/config/i386/constraints.md
> > index 7508d7a58bd..b760e7c221a 100644
> > --- a/gcc/config/i386/constraints.md
> > +++ b/gcc/config/i386/constraints.md
> > @@ -187,7 +187,7 @@ (define_special_memory_constraint "Bm"
> > "@internal Vector memory operand."
> > (match_operand 0 "vector_memory_operand"))
> >
> > -(define_memory_constraint "Bk"
> > +(define_special_memory_constraint "Bk"
> > "@internal TLS address that allows insn using non-integer registers."
> > (and (match_operand 0 "memory_operand")
> > (not (match_test "ix86_gpr_tls_address_pattern_p (op)"))))
> > diff --git a/gcc/testsuite/gcc.target/i386/pr116043.c
> > b/gcc/testsuite/gcc.target/i386/pr116043.c
> > new file mode 100644
> > index 00000000000..76553496c10
> > --- /dev/null
> > +++ b/gcc/testsuite/gcc.target/i386/pr116043.c
> > @@ -0,0 +1,33 @@
> > +/* { dg-do compile } */
> > +/* { dg-options "-mavx512bf16 -O3" } */
> > +/* { dg-final { scan-assembler-not {(?n)lea.*@gottpoff} } } */
> > +
> > +extern __thread int a, c, i, j, k, l;
> > +int *b;
> > +struct d {
> > + int e;
> > +} f, g;
> > +char *h;
> > +
> > +void m(struct d *n) {
> > + b = &k;
> > + for (; n->e; b++, n--) {
> > + i = b && a;
> > + if (i)
> > + j = c;
> > + }
> > +}
> > +
> > +char *o(struct d *n) {
> > + for (; n->e;)
> > + return h;
> > +}
> > +
> > +int q() {
> > + if (l)
> > + return 1;
> > + int p = *o(&g);
> > + m(&f);
> > + m(&g);
> > + l = p;
> > +}
> > --
> > 2.31.1
> >
>
>
> --
> BR,
> Hongtao
--
BR,
Hongtao
