On Fri, Feb 2, 2024 at 11:47 PM H.J. Lu <hjl.to...@gmail.com> wrote:
>
> Changes in v5:
>
> 1. Add pr113689-3.c.
> 2. Use %r10 if ix86_profile_before_prologue () return true.
> 3. Try a callee-saved register which has been saved on stack in the
> prologue.
>
> Changes in v4:
>
> 1. Remove pr113689-3.c.
> 2. Use df_get_live_out.
>
> Changes in v3:
>
> 1. Remove r10_ok.
>
> Changes in v2:
>
> 1. Add int_parameter_registers to machine_function to track integer
> registers used for parameter passing.
> 2. Update x86_64_select_profile_regnum to try %r10 first and use an
> caller-saved register, which isn't used for parameter passing.
>
> ---
> 2 scratch registers, %r10 and %r11, are available at function entry for
> large model profiling. But %r10 may be used by stack realignment and we
> can't use %r10 in this case. Add x86_64_select_profile_regnum to find
> a caller-saved register which isn't live or a callee-saved register
> which has been saved on stack in the prologue at entry for large model
> profiling and sorry if we can't find one.
>
> gcc/
>
> PR target/113689
> * config/i386/i386.cc (set_saved_int_registers_bit): New.
> (test_saved_int_registers_bit): Likewise.
> (ix86_emit_save_regs): Call set_saved_int_registers_bit on
> saved register.
> (ix86_emit_save_regs_using_mov): Likewise.
> (x86_64_select_profile_regnum): New.
> (x86_function_profiler): Call x86_64_select_profile_regnum to
> get a scratch register for large model profiling.
> * config/i386/i386.h (machine_function): Add
> saved_int_registers.
>
> gcc/testsuite/
>
> PR target/113689
> * gcc.target/i386/pr113689-1.c: New file.
> * gcc.target/i386/pr113689-2.c: Likewise.
> * gcc.target/i386/pr113689-3.c: Likewise.
> ---
> gcc/config/i386/i386.cc | 119 ++++++++++++++++++---
> gcc/config/i386/i386.h | 5 +
> gcc/testsuite/gcc.target/i386/pr113689-1.c | 49 +++++++++
> gcc/testsuite/gcc.target/i386/pr113689-2.c | 41 +++++++
> gcc/testsuite/gcc.target/i386/pr113689-3.c | 48 +++++++++
> 5 files changed, 247 insertions(+), 15 deletions(-)
> create mode 100644 gcc/testsuite/gcc.target/i386/pr113689-1.c
> create mode 100644 gcc/testsuite/gcc.target/i386/pr113689-2.c
> create mode 100644 gcc/testsuite/gcc.target/i386/pr113689-3.c
>
> diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
> index b3e7c74846e..1c7aaa4535e 100644
> --- a/gcc/config/i386/i386.cc
> +++ b/gcc/config/i386/i386.cc
> @@ -7387,6 +7387,32 @@ choose_baseaddr (HOST_WIDE_INT cfa_offset, unsigned
> int *align,
> return plus_constant (Pmode, base_reg, base_offset);
> }
>
> +/* Set the integer register REGNO bit in saved_int_registers. */
> +
> +static void
> +set_saved_int_registers_bit (int regno)
> +{
> + if (LEGACY_INT_REGNO_P (regno))
> + cfun->machine->saved_int_registers |= 1 << regno;
> + else
> + cfun->machine->saved_int_registers
> + |= 1 << (regno - FIRST_REX_INT_REG + 8);
> +}
> +
> +/* Return true if the integer register REGNO bit in saved_int_registers
> + is set. */
> +
> +static bool
> +test_saved_int_registers_bit (int regno)
> +{
> + if (LEGACY_INT_REGNO_P (regno))
> + return (cfun->machine->saved_int_registers
> + & (1 << regno)) != 0;
> + else
> + return (cfun->machine->saved_int_registers
> + & (1 << (regno - FIRST_REX_INT_REG + 8))) != 0;
> +}
> +
> /* Emit code to save registers in the prologue. */
>
> static void
> @@ -7403,6 +7429,7 @@ ix86_emit_save_regs (void)
> insn = emit_insn (gen_push (gen_rtx_REG (word_mode, regno),
> TARGET_APX_PPX));
> RTX_FRAME_RELATED_P (insn) = 1;
> + set_saved_int_registers_bit (regno);
> }
> }
> else
> @@ -7415,6 +7442,7 @@ ix86_emit_save_regs (void)
> for (regno = FIRST_PSEUDO_REGISTER - 1; regno >= 0; regno--)
> if (GENERAL_REGNO_P (regno) && ix86_save_reg (regno, true, true))
> {
> + set_saved_int_registers_bit (regno);
> if (aligned)
> {
> regno_list[loaded_regnum++] = regno;
> @@ -7567,6 +7595,7 @@ ix86_emit_save_regs_using_mov (HOST_WIDE_INT cfa_offset)
> {
> ix86_emit_save_reg_using_mov (word_mode, regno, cfa_offset);
> cfa_offset -= UNITS_PER_WORD;
> + set_saved_int_registers_bit (regno);
> }
> }
Do we really need the above handling? I think that we can use
ix86_save_reg directly in x86_64_select_profile_regnum below.
> @@ -22749,6 +22778,48 @@ current_fentry_section (const char **name)
> return true;
> }
>
> +/* Return a caller-saved register which isn't live or a callee-saved
> + register which has been saved on stack in the prologue at entry for
> + profile. */
> +
> +static int
> +x86_64_select_profile_regnum (bool r11_ok ATTRIBUTE_UNUSED)
> +{
> + /* Use %r10 if the profiler is emitted before the prologue or it isn't
> + used by DRAP. */
> + if (ix86_profile_before_prologue ()
> + || !crtl->drap_reg
> + || REGNO (crtl->drap_reg) != R10_REG)
> + return R10_REG;
> +
> + /* The profiler is emitted after the prologue. If there is a
> + caller-saved register which isn't live or a callee-saved
> + register saved on stack in the prologue, use it. */
> +
> + bitmap reg_live = df_get_live_out (ENTRY_BLOCK_PTR_FOR_FN (cfun));
> +
> + int i;
> + for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
> + if (GENERAL_REGNO_P (i)
> + && i != R10_REG
> +#ifdef NO_PROFILE_COUNTERS
> + && (r11_ok || i != R11_REG)
> +#else
> + && i != R11_REG
> +#endif
> + && (!REX2_INT_REGNO_P (i) || TARGET_APX_EGPR)
> + && !fixed_regs[i]
> + && (test_saved_int_registers_bit (i)
> + || (call_used_regs[i]
> + && !REGNO_REG_SET_P (reg_live, i))))
> + return i;
We are scanning the whole hard reg space, so we can use ix86_save_reg
here instead of introducing test_saved_int_registers_bit array. Also,
you can use accessible_reg_set to determine which general register set
is available.
> +
> + sorry ("no register available for profiling %<-mcmodel=large%s%>",
> + ix86_cmodel == CM_LARGE_PIC ? " -fPIC" : "");
> +
> + return INVALID_REGNUM;
> +}
> +
> /* Output assembler code to FILE to increment profiler label # LABELNO
> for profiling a function entry. */
> void
> @@ -22783,42 +22854,60 @@ x86_function_profiler (FILE *file, int labelno
> ATTRIBUTE_UNUSED)
> fprintf (file, "\tleaq\t%sP%d(%%rip), %%r11\n", LPREFIX, labelno);
> #endif
>
> + int scratch;
> + const char *reg_prefix;
> + const char *reg;
> +
> if (!TARGET_PECOFF)
> {
> switch (ix86_cmodel)
> {
> case CM_LARGE:
> - /* NB: R10 is caller-saved. Although it can be used as a
> - static chain register, it is preserved when calling
> - mcount for nested functions. */
> + scratch = x86_64_select_profile_regnum (true);
> + reg = hi_reg_name[scratch];
> + reg_prefix = LEGACY_INT_REGNO_P (scratch) ? "r" : "";
Oh... please rather construct a complete reg name here and avoid using
reg_prefix below.
> if (ASSEMBLER_DIALECT == ASM_INTEL)
> - fprintf (file, "1:\tmovabs\tr10, OFFSET FLAT:%s\n"
> - "\tcall\tr10\n", mcount_name);
> + fprintf (file,
> + "1:\tmovabs\t%s%s, OFFSET FLAT:%s\n"
> + "\tcall\t%s%s\n",
> + reg_prefix, reg, mcount_name, reg_prefix, reg);
> else
> - fprintf (file, "1:\tmovabsq\t$%s, %%r10\n\tcall\t*%%r10\n",
> - mcount_name);
> + fprintf (file,
> + "1:\tmovabsq\t$%s, %%%s%s\n\tcall\t*%%%s%s\n",
> + mcount_name, reg_prefix, reg, reg_prefix, reg);
> break;
> case CM_LARGE_PIC:
> #ifdef NO_PROFILE_COUNTERS
> + scratch = x86_64_select_profile_regnum (false);
> + reg = hi_reg_name[scratch];
> + reg_prefix = LEGACY_INT_REGNO_P (scratch) ? "r" : "";
Also here, please construct a complete reg name here.
Uros.
> if (ASSEMBLER_DIALECT == ASM_INTEL)
> {
> fprintf (file, "1:movabs\tr11, "
> "OFFSET FLAT:_GLOBAL_OFFSET_TABLE_-1b\n");
> - fprintf (file, "\tlea\tr10, 1b[rip]\n");
> - fprintf (file, "\tadd\tr10, r11\n");
> + fprintf (file, "\tlea\t%s%s, 1b[rip]\n",
> + reg_prefix, reg);
> + fprintf (file, "\tadd\t%s%s, r11\n",
> + reg_prefix, reg);
> fprintf (file, "\tmovabs\tr11, OFFSET FLAT:%s@PLTOFF\n",
> mcount_name);
> - fprintf (file, "\tadd\tr10, r11\n");
> - fprintf (file, "\tcall\tr10\n");
> + fprintf (file, "\tadd\t%s%s, r11\n",
> + reg_prefix, reg);
> + fprintf (file, "\tcall\t%s%s\n",
> + reg_prefix, reg);
> break;
> }
> fprintf (file,
> "1:\tmovabsq\t$_GLOBAL_OFFSET_TABLE_-1b, %%r11\n");
> - fprintf (file, "\tleaq\t1b(%%rip), %%r10\n");
> - fprintf (file, "\taddq\t%%r11, %%r10\n");
> + fprintf (file, "\tleaq\t1b(%%rip), %%%s%s\n",
> + reg_prefix, reg);
> + fprintf (file, "\taddq\t%%r11, %%%s%s\n",
> + reg_prefix, reg);
> fprintf (file, "\tmovabsq\t$%s@PLTOFF, %%r11\n", mcount_name);
> - fprintf (file, "\taddq\t%%r11, %%r10\n");
> - fprintf (file, "\tcall\t*%%r10\n");
> + fprintf (file, "\taddq\t%%r11, %%%s%s\n",
> + reg_prefix, reg);
> + fprintf (file, "\tcall\t*%%%s%s\n",
> + reg_prefix, reg);
> #else
> sorry ("profiling %<-mcmodel=large%> with PIC is not
> supported");
> #endif
> diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
> index 35ce8b00d36..33821a04074 100644
> --- a/gcc/config/i386/i386.h
> +++ b/gcc/config/i386/i386.h
> @@ -2847,6 +2847,11 @@ struct GTY(()) machine_function {
> /* True if red zone is used. */
> BOOL_BITFIELD red_zone_used : 1;
>
> + /* Bit mask for integer registers saved on stack in prologue. The
> + lower 8 bits are for legacy registers and the upper 8 bits are
> + for r8-r15. */
> + unsigned int saved_int_registers : 16;
> +
> /* The largest alignment, in bytes, of stack slot actually used. */
> unsigned int max_used_stack_alignment;
>
> diff --git a/gcc/testsuite/gcc.target/i386/pr113689-1.c
> b/gcc/testsuite/gcc.target/i386/pr113689-1.c
> new file mode 100644
> index 00000000000..8285c0a07b7
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr113689-1.c
> @@ -0,0 +1,49 @@
> +/* { dg-do run { target { lp64 && fpic } } } */
> +/* { dg-options "-O2 -fno-pic -fprofile -mcmodel=large" } */
> +
> +#include <stdarg.h>
> +
> +__attribute__((noipa))
> +void
> +bar (int a1, int a2, int a3, int a4, int a5, int a6,
> + char *x, char *y, int *z)
> +{
> + if (a1 != 1)
> + __builtin_abort ();
> + if (a2 != 2)
> + __builtin_abort ();
> + if (a3 != 3)
> + __builtin_abort ();
> + if (a4 != 4)
> + __builtin_abort ();
> + if (a5 != 5)
> + __builtin_abort ();
> + if (a6 != 6)
> + __builtin_abort ();
> + x[0] = 42;
> + y[0] = 42;
> + if (z[0] != 16)
> + __builtin_abort ();
> +}
> +
> +__attribute__((noipa))
> +void
> +foo (int c, int d, int e, int f, int g, int h, int z, ...)
> +{
> + typedef char B[32];
> + B b __attribute__((aligned (32)));
> + va_list ap;
> + va_start (ap, z);
> + double x = va_arg (ap, double);
> + if (x > 40.0)
> + __builtin_abort ();
> + bar (c, d, e, f, g, h, &b[0], __builtin_alloca (z), &z);
> + va_end (ap);
> +}
> +
> +int
> +main ()
> +{
> + foo (1, 2, 3, 4, 5, 6, 16, 38.0);
> + return 0;
> +}
> diff --git a/gcc/testsuite/gcc.target/i386/pr113689-2.c
> b/gcc/testsuite/gcc.target/i386/pr113689-2.c
> new file mode 100644
> index 00000000000..2e5579ac546
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr113689-2.c
> @@ -0,0 +1,41 @@
> +/* { dg-do run { target { lp64 && fpic } } } */
> +/* { dg-options "-O2 -fpic -fprofile -mcmodel=large" } */
> +
> +__attribute__((noipa))
> +void
> +bar (int a1, int a2, int a3, int a4, int a5, int a6,
> + char *x, char *y, int *z)
> +{
> + if (a1 != 1)
> + __builtin_abort ();
> + if (a2 != 2)
> + __builtin_abort ();
> + if (a3 != 3)
> + __builtin_abort ();
> + if (a4 != 4)
> + __builtin_abort ();
> + if (a5 != 5)
> + __builtin_abort ();
> + if (a6 != 6)
> + __builtin_abort ();
> + x[0] = 42;
> + y[0] = 42;
> + if (z[0] != 16)
> + __builtin_abort ();
> +}
> +
> +__attribute__((noipa))
> +void
> +foo (int c, int d, int e, int f, int g, int h, int z)
> +{
> + typedef char B[32];
> + B b __attribute__((aligned (32)));
> + bar (c, d, e, f, g, h, &b[0], __builtin_alloca (z), &z);
> +}
> +
> +int
> +main ()
> +{
> + foo (1, 2, 3, 4, 5, 6, 16);
> + return 0;
> +}
> diff --git a/gcc/testsuite/gcc.target/i386/pr113689-3.c
> b/gcc/testsuite/gcc.target/i386/pr113689-3.c
> new file mode 100644
> index 00000000000..dab75190635
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr113689-3.c
> @@ -0,0 +1,48 @@
> +/* { dg-do run { target { lp64 && fpic } } } */
> +/* { dg-options "-O2 -fpic -fprofile -mcmodel=large" } */
> +
> +#include <stdarg.h>
> +
> +__attribute__((noipa))
> +void
> +bar (char *x, char *y, int *z)
> +{
> + x[0] = 42;
> + y[0] = 42;
> + if (z[0] != 16)
> + __builtin_abort ();
> +}
> +
> +__attribute__((noipa))
> +void
> +foo (int a1, int a2, int a3, int a4, int a5, int a6, int z, ...)
> +{
> + typedef char B[32];
> + B b __attribute__((aligned (32)));
> + va_list ap;
> + va_start (ap, z);
> + double x = va_arg (ap, double);
> + if (x > 40.0)
> + __builtin_abort ();
> + if (a1 != 1)
> + __builtin_abort ();
> + if (a2 != 2)
> + __builtin_abort ();
> + if (a3 != 3)
> + __builtin_abort ();
> + if (a4 != 4)
> + __builtin_abort ();
> + if (a5 != 5)
> + __builtin_abort ();
> + if (a6 != 6)
> + __builtin_abort ();
> + bar (&b[0], __builtin_alloca (z), &z);
> + va_end (ap);
> +}
> +
> +int
> +main ()
> +{
> + foo (1, 2, 3, 4, 5, 6, 16, 38.0);
> + return 0;
> +}
> --
> 2.43.0
>
