On Sun, Sep 8, 2024 at 12:10 AM Uros Bizjak <[email protected]> wrote: > > On Fri, Sep 6, 2024 at 2:24 PM H.J. Lu <[email protected]> wrote: > > > > Don't use temp for a PARALLEL BLKmode argument of an EXPR_LIST expression > > in a TImode register. Otherwise, the TImode variable will be put in > > the GPR save area which guarantees only 8-byte alignment. > > > > gcc/ > > > > PR target/116621 > > * config/i386/i386.cc (ix86_gimplify_va_arg): Don't use temp for > > a PARALLEL BLKmode container of an EXPR_LIST expression in a > > TImode register. > > > > gcc/testsuite/ > > > > PR target/116621 > > * gcc.target/i386/pr116621.c: New test. > > LGTM.
OK to backport to release branches? > Thanks, > Uros. > > > > > Signed-off-by: H.J. Lu <[email protected]> > > --- > > gcc/config/i386/i386.cc | 22 ++++++++++-- > > gcc/testsuite/gcc.target/i386/pr116621.c | 43 ++++++++++++++++++++++++ > > 2 files changed, 63 insertions(+), 2 deletions(-) > > create mode 100644 gcc/testsuite/gcc.target/i386/pr116621.c > > > > diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc > > index 707b75a6d5d..45320124b91 100644 > > --- a/gcc/config/i386/i386.cc > > +++ b/gcc/config/i386/i386.cc > > @@ -4908,13 +4908,31 @@ ix86_gimplify_va_arg (tree valist, tree type, > > gimple_seq *pre_p, > > > > examine_argument (nat_mode, type, 0, &needed_intregs, > > &needed_sseregs); > > > > - need_temp = (!REG_P (container) > > + bool container_in_reg = false; > > + if (REG_P (container)) > > + container_in_reg = true; > > + else if (GET_CODE (container) == PARALLEL > > + && GET_MODE (container) == BLKmode > > + && XVECLEN (container, 0) == 1) > > + { > > + /* Check if it is a PARALLEL BLKmode container of an EXPR_LIST > > + expression in a TImode register. In this case, temp isn't > > + needed. Otherwise, the TImode variable will be put in the > > + GPR save area which guarantees only 8-byte alignment. */ > > + rtx x = XVECEXP (container, 0, 0); > > + if (GET_CODE (x) == EXPR_LIST > > + && REG_P (XEXP (x, 0)) > > + && XEXP (x, 1) == const0_rtx) > > + container_in_reg = true; > > + } > > + > > + need_temp = (!container_in_reg > > && ((needed_intregs && TYPE_ALIGN (type) > 64) > > || TYPE_ALIGN (type) > 128)); > > > > /* In case we are passing structure, verify that it is consecutive > > block > > on the register save area. If not we need to do moves. */ > > - if (!need_temp && !REG_P (container)) > > + if (!need_temp && !container_in_reg) > > { > > /* Verify that all registers are strictly consecutive */ > > if (SSE_REGNO_P (REGNO (XEXP (XVECEXP (container, 0, 0), 0)))) > > diff --git a/gcc/testsuite/gcc.target/i386/pr116621.c > > b/gcc/testsuite/gcc.target/i386/pr116621.c > > new file mode 100644 > > index 00000000000..704266458a8 > > --- /dev/null > > +++ b/gcc/testsuite/gcc.target/i386/pr116621.c > > @@ -0,0 +1,43 @@ > > +/* { dg-do run } */ > > +/* { dg-options "-O2" } */ > > + > > +#include <stdarg.h> > > +#include <string.h> > > + > > +union S8302 > > +{ > > + union > > + { > > + double b; > > + int c; > > + } a; > > + long double d; > > + unsigned short int f[5]; > > +}; > > + > > +union S8302 s8302; > > +extern void check8302va (int i, ...); > > + > > +int > > +main (void) > > +{ > > + memset (&s8302, '\0', sizeof (s8302)); > > + s8302.a.b = -221438.250000; > > + check8302va (1, s8302); > > + return 0; > > +} > > + > > +__attribute__((noinline, noclone)) > > +void > > +check8302va (int z, ...) > > +{ > > + union S8302 arg, *p; > > + va_list ap; > > + > > + __builtin_va_start (ap, z); > > + p = &s8302; > > + arg = __builtin_va_arg (ap, union S8302); > > + if (p->a.b != arg.a.b) > > + __builtin_abort (); > > + __builtin_va_end (ap); > > +} > > -- > > 2.46.0 > > -- H.J.
