On Thu, Mar 11, 2021 at 11:22 PM H.J. Lu <hjl.to...@gmail.com> wrote:
>
> Update 'P' operand modifier for -fno-plt to support inline assembly
> statements. In 64-bit, we can always load function address with
> @GOTPCREL. In 32-bit, we load function address with @GOT only for
> non-PIC since PIC register may not be available at call site.
>
> gcc/
>
> PR target/99504
> * config/i386/i386.c (ix86_print_operand): Update 'P' handling
> for -fno-plt.
>
> gcc/testsuite/
>
> PR target/99504
> * gcc.target/i386/pr99530-1.c: New test.
> * gcc.target/i386/pr99530-2.c: Likewise.
> * gcc.target/i386/pr99530-3.c: Likewise.
> * gcc.target/i386/pr99530-4.c: Likewise.
> * gcc.target/i386/pr99530-5.c: Likewise.
> * gcc.target/i386/pr99530-6.c: Likewise.
> ---
> gcc/config/i386/i386.c | 33 +++++++++++++++++++++--
> gcc/testsuite/gcc.target/i386/pr99530-1.c | 11 ++++++++
> gcc/testsuite/gcc.target/i386/pr99530-2.c | 11 ++++++++
> gcc/testsuite/gcc.target/i386/pr99530-3.c | 11 ++++++++
> gcc/testsuite/gcc.target/i386/pr99530-4.c | 11 ++++++++
> gcc/testsuite/gcc.target/i386/pr99530-5.c | 11 ++++++++
> gcc/testsuite/gcc.target/i386/pr99530-6.c | 11 ++++++++
> 7 files changed, 97 insertions(+), 2 deletions(-)
> create mode 100644 gcc/testsuite/gcc.target/i386/pr99530-1.c
> create mode 100644 gcc/testsuite/gcc.target/i386/pr99530-2.c
> create mode 100644 gcc/testsuite/gcc.target/i386/pr99530-3.c
> create mode 100644 gcc/testsuite/gcc.target/i386/pr99530-4.c
> create mode 100644 gcc/testsuite/gcc.target/i386/pr99530-5.c
> create mode 100644 gcc/testsuite/gcc.target/i386/pr99530-6.c
>
> diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
> index 2603333f87b..8733fcecf65 100644
> --- a/gcc/config/i386/i386.c
> +++ b/gcc/config/i386/i386.c
> @@ -12701,7 +12701,8 @@ print_reg (rtx x, int code, FILE *file)
> y -- print "st(0)" instead of "st" as a register.
> d -- print duplicated register operand for AVX instruction.
> D -- print condition for SSE cmp instruction.
> - P -- if PIC, print an @PLT suffix.
> + P -- if PIC, print an @PLT suffix. For -fno-plt, load function
> + address from GOT.
> p -- print raw symbol name.
> X -- don't print any sort of PIC '@' suffix for a symbol.
> & -- print some in-use local-dynamic symbol name.
> @@ -13445,7 +13446,35 @@ ix86_print_operand (FILE *file, rtx x, int code)
> x = const0_rtx;
> }
>
> - if (code != 'P' && code != 'p')
> + if (code == 'P')
> + {
> + if (current_output_insn == NULL_RTX
> + && (TARGET_64BIT || (!flag_pic && HAVE_AS_IX86_GOT32X))
> + && !TARGET_PECOFF
> + && !TARGET_MACHO
> + && ix86_cmodel != CM_LARGE
> + && ix86_cmodel != CM_LARGE_PIC
> + && GET_CODE (x) == SYMBOL_REF
> + && SYMBOL_REF_FUNCTION_P (x)
> + && (!flag_plt
> + || (SYMBOL_REF_DECL (x)
> + && lookup_attribute ("noplt",
> + DECL_ATTRIBUTES (SYMBOL_REF_DECL
> (x)))))
> + && !SYMBOL_REF_LOCAL_P (x))
You can use ix86_force_load_from_GOT_p instead.
Uros.
> + {
> + /* For inline assembly statement, load function address
> + from GOT with 'P' operand modifier to avoid PLT.
> + NB: This works only with call or jmp. */
> + const char *xasm;
> + if (TARGET_64BIT)
> + xasm = "{*%p0@GOTPCREL(%%rip)|[QWORD PTR %p0@GOTPCREL[rip]]}";
> + else
> + xasm = "{*%p0@GOT|[DWORD PTR %p0@GOT]}";
> + output_asm_insn (xasm, &x);
> + return;
> + }
> + }
> + else if (code != 'p')
> {
> if (CONST_INT_P (x))
> {
> diff --git a/gcc/testsuite/gcc.target/i386/pr99530-1.c
> b/gcc/testsuite/gcc.target/i386/pr99530-1.c
> new file mode 100644
> index 00000000000..080d7cc9399
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr99530-1.c
> @@ -0,0 +1,11 @@
> +/* { dg-do compile { target { i?86-*-linux* x86_64-*-linux* } } } */
> +/* { dg-require-effective-target lp64 } */
> +/* { dg-options "-O2 -fpic -mcmodel=large -fno-plt" } */
> +/* { dg-final { scan-assembler-not "foo@GOTPCREL" } } */
> +
> +extern void foo (void);
> +void
> +bar (void)
> +{
> + asm ("call %P0" : : "X" (foo));
> +}
> diff --git a/gcc/testsuite/gcc.target/i386/pr99530-2.c
> b/gcc/testsuite/gcc.target/i386/pr99530-2.c
> new file mode 100644
> index 00000000000..9808957d624
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr99530-2.c
> @@ -0,0 +1,11 @@
> +/* { dg-do compile { target { i?86-*-linux* x86_64-*-linux* } } } */
> +/* { dg-require-effective-target lp64 } */
> +/* { dg-options "-O2 -fno-pic -mcmodel=large -fno-plt" } */
> +/* { dg-final { scan-assembler-not "foo@GOTPCREL" } } */
> +
> +extern void foo (void);
> +void
> +bar (void)
> +{
> + asm ("call %P0" : : "X" (foo));
> +}
> diff --git a/gcc/testsuite/gcc.target/i386/pr99530-3.c
> b/gcc/testsuite/gcc.target/i386/pr99530-3.c
> new file mode 100644
> index 00000000000..22fe81b25f2
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr99530-3.c
> @@ -0,0 +1,11 @@
> +/* { dg-do compile { target { i?86-*-linux* x86_64-*-linux* } } } */
> +/* { dg-options "-O2 -fno-pic -fno-plt" } */
> +/* { dg-final { scan-assembler "call\[ \t\]+\[*\]foo@GOTPCREL" { target { !
> ia32 } } } } */
> +/* { dg-final { scan-assembler "call\[ \t\]+\[*\]foo@GOT" { target { ia32 &&
> got32x_reloc } } } } */
> +
> +extern void foo (void);
> +void
> +bar (void)
> +{
> + asm ("call %P0" : : "X" (foo));
> +}
> diff --git a/gcc/testsuite/gcc.target/i386/pr99530-4.c
> b/gcc/testsuite/gcc.target/i386/pr99530-4.c
> new file mode 100644
> index 00000000000..aba0b5d7892
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr99530-4.c
> @@ -0,0 +1,11 @@
> +/* { dg-do compile { target { i?86-*-linux* x86_64-*-linux* } } } */
> +/* { dg-options "-O2 -fpic -fno-plt" } */
> +/* { dg-final { scan-assembler "call\[ \t\]+\[*\]foo@GOTPCREL" { target { !
> ia32 } } } } */
> +/* { dg-final { scan-assembler-not "foo@GOT" { target { ia32 } } } } */
> +
> +extern void foo (void);
> +void
> +bar (void)
> +{
> + asm ("call %P0" : : "X" (foo));
> +}
> diff --git a/gcc/testsuite/gcc.target/i386/pr99530-5.c
> b/gcc/testsuite/gcc.target/i386/pr99530-5.c
> new file mode 100644
> index 00000000000..02c5799d273
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr99530-5.c
> @@ -0,0 +1,11 @@
> +/* { dg-do compile { target { i?86-*-linux* x86_64-*-linux* } } } */
> +/* { dg-options "-O2 -fno-pic" } */
> +/* { dg-final { scan-assembler "call\[ \t\]+\[*\]foo@GOTPCREL" { target { !
> ia32 } } } } */
> +/* { dg-final { scan-assembler "call\[ \t\]+\[*\]foo@GOT" { target { ia32 &&
> got32x_reloc } } } } */
> +
> +extern void foo (void) __attribute__ ((noplt));
> +void
> +bar (void)
> +{
> + asm ("call %P0" : : "X" (foo));
> +}
> diff --git a/gcc/testsuite/gcc.target/i386/pr99530-6.c
> b/gcc/testsuite/gcc.target/i386/pr99530-6.c
> new file mode 100644
> index 00000000000..0dfdd3752f7
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr99530-6.c
> @@ -0,0 +1,11 @@
> +/* { dg-do compile { target { i?86-*-linux* x86_64-*-linux* } } } */
> +/* { dg-options "-O2 -fpic" } */
> +/* { dg-final { scan-assembler "call\[ \t\]+\[*\]foo@GOTPCREL" { target { !
> ia32 } } } } */
> +/* { dg-final { scan-assembler-not "foo@GOT" { target { ia32 } } } } */
> +
> +extern void foo (void) __attribute__ ((noplt));
> +void
> +bar (void)
> +{
> + asm ("call %P0" : : "X" (foo));
> +}
> --
> 2.29.2
>
