On Mon, Apr 14, 2025 at 7:36 AM H.J. Lu <hjl.to...@gmail.com> wrote:
>
> Don't use red-zone when there are no caller-saved registers and APX is
> enabled since 128-byte red-zone is too small for 31 GPRs.
>
> gcc/
>
> PR target/119784
> * config/i386/i386.cc (ix86_using_red_zone): Don't use red-zone
> with APX and no caller-saved registers.
>
> gcc/testsuite/
>
> PR target/119784
> * gcc.target/i386/pr119784a.c: New test.
> * gcc.target/i386/pr119784b.c: Likewise.
>
> Signed-off-by: H.J. Lu <hjl.to...@gmail.com>
> ---
> gcc/config/i386/i386.cc | 6 ++
> gcc/testsuite/gcc.target/i386/pr119784a.c | 96 +++++++++++++++++++++++
> gcc/testsuite/gcc.target/i386/pr119784b.c | 87 ++++++++++++++++++++
> 3 files changed, 189 insertions(+)
> create mode 100644 gcc/testsuite/gcc.target/i386/pr119784a.c
> create mode 100644 gcc/testsuite/gcc.target/i386/pr119784b.c
>
> diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
> index 4f8380c4a58..91af239d484 100644
> --- a/gcc/config/i386/i386.cc
> +++ b/gcc/config/i386/i386.cc
> @@ -458,6 +458,9 @@ int ix86_arch_specified;
> indirect thunk pushes the return address onto stack, destroying
> red-zone.
>
> + NB: Don't use red-zone for functions with no_caller_saved_registers
> + when APX is enabled since 128-byte red-zone is too small for 31 GPRs.
> +
> TODO: If we can reserve the first 2 WORDs, for PUSH and, another
> for CALL, in red-zone, we can allow local indirect jumps with
> indirect thunk. */
> @@ -467,6 +470,9 @@ ix86_using_red_zone (void)
> {
> return (TARGET_RED_ZONE
> && !TARGET_64BIT_MS_ABI
> + && (!TARGET_APX_F
Could we use !TARGET_APX_EGPR, it's more clear.
Others LGTM, but please wait for a while in case Uros has a different opinion.
> + || (cfun->machine->call_saved_registers
> + != TYPE_NO_CALLER_SAVED_REGISTERS))
> && (!cfun->machine->has_local_indirect_jump
> || cfun->machine->indirect_branch_type ==
> indirect_branch_keep));
> }
> diff --git a/gcc/testsuite/gcc.target/i386/pr119784a.c
> b/gcc/testsuite/gcc.target/i386/pr119784a.c
> new file mode 100644
> index 00000000000..8a119d4cc1f
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr119784a.c
> @@ -0,0 +1,96 @@
> +/* { dg-do compile { target { *-*-linux* && lp64 } } } */
> +/* { dg-options "-O2 -fno-pic -mtune=generic -mgeneral-regs-only -mapxf
> -mtune-ctrl=prologue_using_move,epilogue_using_move" } */
> +/* Keep labels and directives ('.cfi_startproc', '.cfi_endproc'). */
> +/* { dg-final { check-function-bodies "**" "" "" { target "*-*-*" } {^\t?\.}
> } } */
> +
> +/* start must save and restore all caller saved registers. */
> +
> +/*
> +**start:
> +**.LFB[0-9]+:
> +** .cfi_startproc
> +** subq \$248, %rsp
> +**...
> +** movq %rax, \(%rsp\)
> +** movq %rdx, 8\(%rsp\)
> +** movq %rcx, 16\(%rsp\)
> +** movq %rbx, 24\(%rsp\)
> +** movq %rsi, 32\(%rsp\)
> +** movq %rdi, 40\(%rsp\)
> +**...
> +** movq %rbp, 48\(%rsp\)
> +** movq %r8, 56\(%rsp\)
> +** movq %r9, 64\(%rsp\)
> +** movq %r10, 72\(%rsp\)
> +** movq %r11, 80\(%rsp\)
> +** movq %r12, 88\(%rsp\)
> +** movq %r13, 96\(%rsp\)
> +** movq %r14, 104\(%rsp\)
> +** movq %r15, 112\(%rsp\)
> +** movq %r16, 120\(%rsp\)
> +** movq %r17, 128\(%rsp\)
> +** movq %r18, 136\(%rsp\)
> +** movq %r19, 144\(%rsp\)
> +** movq %r20, 152\(%rsp\)
> +** movq %r21, 160\(%rsp\)
> +** movq %r22, 168\(%rsp\)
> +** movq %r23, 176\(%rsp\)
> +** movq %r24, 184\(%rsp\)
> +** movq %r25, 192\(%rsp\)
> +** movq %r26, 200\(%rsp\)
> +** movq %r27, 208\(%rsp\)
> +** movq %r28, 216\(%rsp\)
> +** movq %r29, 224\(%rsp\)
> +** movq %r30, 232\(%rsp\)
> +** movq %r31, 240\(%rsp\)
> +**...
> +** call \*code\(%rip\)
> +** movq \(%rsp\), %rax
> +** movq 8\(%rsp\), %rdx
> +** movq 16\(%rsp\), %rcx
> +** movq 24\(%rsp\), %rbx
> +** movq 32\(%rsp\), %rsi
> +** movq 40\(%rsp\), %rdi
> +** movq 48\(%rsp\), %rbp
> +** movq 56\(%rsp\), %r8
> +** movq 64\(%rsp\), %r9
> +** movq 72\(%rsp\), %r10
> +** movq 80\(%rsp\), %r11
> +** movq 88\(%rsp\), %r12
> +** movq 96\(%rsp\), %r13
> +** movq 104\(%rsp\), %r14
> +** movq 112\(%rsp\), %r15
> +** movq 120\(%rsp\), %r16
> +** movq 128\(%rsp\), %r17
> +** movq 136\(%rsp\), %r18
> +** movq 144\(%rsp\), %r19
> +** movq 152\(%rsp\), %r20
> +** movq 160\(%rsp\), %r21
> +** movq 168\(%rsp\), %r22
> +** movq 176\(%rsp\), %r23
> +** movq 184\(%rsp\), %r24
> +** movq 192\(%rsp\), %r25
> +** movq 200\(%rsp\), %r26
> +** movq 208\(%rsp\), %r27
> +** movq 216\(%rsp\), %r28
> +** movq 224\(%rsp\), %r29
> +** movq 232\(%rsp\), %r30
> +** movq 240\(%rsp\), %r31
> +** addq \$248, %rsp
> +**...
> +** ret
> +** .cfi_endproc
> +**...
> +*/
> +
> +#define DONT_SAVE_REGS __attribute__((no_callee_saved_registers))
> +#define SAVE_REGS __attribute__((no_caller_saved_registers))
> +
> +typedef DONT_SAVE_REGS void (*op_t)(void);
> +
> +extern op_t code[];
> +
> +SAVE_REGS void start()
> +{
> + code[0]();
> +}
> diff --git a/gcc/testsuite/gcc.target/i386/pr119784b.c
> b/gcc/testsuite/gcc.target/i386/pr119784b.c
> new file mode 100644
> index 00000000000..c6761976ed6
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr119784b.c
> @@ -0,0 +1,87 @@
> +/* { dg-do compile { target { *-*-linux* && x32 } } } */
> +/* { dg-options "-O2 -fno-pic -mtune=generic -mgeneral-regs-only -mapxf
> -mtune-ctrl=prologue_using_move,epilogue_using_move" } */
> +/* Keep labels and directives ('.cfi_startproc', '.cfi_endproc'). */
> +/* { dg-final { check-function-bodies "**" "" "" { target "*-*-*" } {^\t?\.}
> } } */
> +
> +/* start must save and restore all caller saved registers. */
> +
> +/*
> +**start:
> +**.LFB[0-9]+:
> +** .cfi_startproc
> +** subl \$248, %esp
> +**...
> +** movq %rax, \(%rsp\)
> +** movq %rdx, 8\(%rsp\)
> +** movq %rcx, 16\(%rsp\)
> +** movq %rbx, 24\(%rsp\)
> +** movq %rsi, 32\(%rsp\)
> +** movq %rdi, 40\(%rsp\)
> +**...
> +** movq %rbp, 48\(%rsp\)
> +** movq %r8, 56\(%rsp\)
> +** movq %r9, 64\(%rsp\)
> +** movq %r10, 72\(%rsp\)
> +** movq %r11, 80\(%rsp\)
> +** movq %r12, 88\(%rsp\)
> +** movq %r13, 96\(%rsp\)
> +** movq %r14, 104\(%rsp\)
> +** movq %r15, 112\(%rsp\)
> +** movq %r16, 120\(%rsp\)
> +** movq %r17, 128\(%rsp\)
> +** movq %r18, 136\(%rsp\)
> +** movq %r19, 144\(%rsp\)
> +** movq %r20, 152\(%rsp\)
> +** movq %r21, 160\(%rsp\)
> +** movq %r22, 168\(%rsp\)
> +** movq %r23, 176\(%rsp\)
> +** movq %r24, 184\(%rsp\)
> +** movq %r25, 192\(%rsp\)
> +** movq %r26, 200\(%rsp\)
> +** movq %r27, 208\(%rsp\)
> +** movq %r28, 216\(%rsp\)
> +** movq %r29, 224\(%rsp\)
> +** movq %r30, 232\(%rsp\)
> +** movq %r31, 240\(%rsp\)
> +**...
> +** movl code\(%rip\), %ebp
> +** call \*%rbp
> +** movq \(%rsp\), %rax
> +** movq 8\(%rsp\), %rdx
> +** movq 16\(%rsp\), %rcx
> +** movq 24\(%rsp\), %rbx
> +** movq 32\(%rsp\), %rsi
> +** movq 40\(%rsp\), %rdi
> +** movq 48\(%rsp\), %rbp
> +** movq 56\(%rsp\), %r8
> +** movq 64\(%rsp\), %r9
> +** movq 72\(%rsp\), %r10
> +** movq 80\(%rsp\), %r11
> +** movq 88\(%rsp\), %r12
> +** movq 96\(%rsp\), %r13
> +** movq 104\(%rsp\), %r14
> +** movq 112\(%rsp\), %r15
> +** movq 120\(%rsp\), %r16
> +** movq 128\(%rsp\), %r17
> +** movq 136\(%rsp\), %r18
> +** movq 144\(%rsp\), %r19
> +** movq 152\(%rsp\), %r20
> +** movq 160\(%rsp\), %r21
> +** movq 168\(%rsp\), %r22
> +** movq 176\(%rsp\), %r23
> +** movq 184\(%rsp\), %r24
> +** movq 192\(%rsp\), %r25
> +** movq 200\(%rsp\), %r26
> +** movq 208\(%rsp\), %r27
> +** movq 216\(%rsp\), %r28
> +** movq 224\(%rsp\), %r29
> +** movq 232\(%rsp\), %r30
> +** movq 240\(%rsp\), %r31
> +** addl \$248, %esp
> +**...
> +** ret
> +** .cfi_endproc
> +**...
> +*/
> +
> +#include "pr119784a.c"
> --
> 2.49.0
>
--
BR,
Hongtao
