When assembler directives for DWARF frame unwind is enabled, generate
the .cfi_undefined directive for unsaved callee-saved registers which
have been used in the function.
gcc/
PR target/38534
* config/i386/i386.cc (ix86_post_cfi_startproc): New.
(TARGET_ASM_POST_CFI_STARTPROC): Likewise.
gcc/testsuite/
PR target/38534
* gcc.target/i386/no-callee-saved-19.c: New test.
* gcc.target/i386/no-callee-saved-20.c: Likewise.
* gcc.target/i386/pr38534-7.c: Likewise.
* gcc.target/i386/pr38534-8.c: Likewise.
---
gcc/config/i386/i386.cc | 37 +++++++++++++++++++
.../gcc.target/i386/no-callee-saved-19.c | 17 +++++++++
.../gcc.target/i386/no-callee-saved-20.c | 12 ++++++
gcc/testsuite/gcc.target/i386/pr38534-7.c | 18 +++++++++
gcc/testsuite/gcc.target/i386/pr38534-8.c | 13 +++++++
5 files changed, 97 insertions(+)
create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-19.c
create mode 100644 gcc/testsuite/gcc.target/i386/no-callee-saved-20.c
create mode 100644 gcc/testsuite/gcc.target/i386/pr38534-7.c
create mode 100644 gcc/testsuite/gcc.target/i386/pr38534-8.c
diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
index b3e7c74846e..d4c10a5ef9b 100644
--- a/gcc/config/i386/i386.cc
+++ b/gcc/config/i386/i386.cc
@@ -22662,6 +22662,40 @@ x86_output_mi_thunk (FILE *file, tree thunk_fndecl,
HOST_WIDE_INT delta,
flag_force_indirect_call = saved_flag_force_indirect_call;
}
+/* Implement TARGET_ASM_POST_CFI_STARTPROC. Triggered after a
+ .cfi_startproc directive is emitted into the assembly file.
+ When assembler directives for DWARF frame unwind is enabled,
+ output the .cfi_undefined directive for unsaved callee-saved
+ registers which have been used in the function. */
+
+void
+ix86_post_cfi_startproc (FILE *f, tree)
+{
+ if ((cfun->machine->call_saved_registers
+ == TYPE_NO_CALLEE_SAVED_REGISTERS)
+ && dwarf2out_do_cfi_asm ())
+ for (int i = 0; i < FIRST_PSEUDO_REGISTER; i++)
+ if (df_regs_ever_live_p (i)
+ && !fixed_regs[i]
+ && !call_used_regs[i]
+ && !STACK_REGNO_P (i)
+ && !MMX_REGNO_P (i))
+ {
+ if (LEGACY_INT_REGNO_P (i))
+ {
+ if (TARGET_64BIT)
+ asm_fprintf (f, "\t.cfi_undefined r%s\n",
+ hi_reg_name[i]);
+ else
+ asm_fprintf (f, "\t.cfi_undefined e%s\n",
+ hi_reg_name[i]);
+ }
+ else
+ asm_fprintf (f, "\t.cfi_undefined %s\n",
+ hi_reg_name[i]);
+ }
+}
+
static void
x86_file_start (void)
{
@@ -26281,6 +26315,9 @@ static const scoped_attribute_specs *const
ix86_attribute_table[] =
#undef TARGET_ASM_CAN_OUTPUT_MI_THUNK
#define TARGET_ASM_CAN_OUTPUT_MI_THUNK x86_can_output_mi_thunk
+#undef TARGET_ASM_POST_CFI_STARTPROC
+#define TARGET_ASM_POST_CFI_STARTPROC ix86_post_cfi_startproc
+
#undef TARGET_ASM_FILE_START
#define TARGET_ASM_FILE_START x86_file_start
diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-19.c
b/gcc/testsuite/gcc.target/i386/no-callee-saved-19.c
new file mode 100644
index 00000000000..60a492cffd3
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-19.c
@@ -0,0 +1,17 @@
+/* { dg-do assemble { target *-*-linux* *-*-gnu* } } */
+/* { dg-options "-save-temps -march=tigerlake -O2
-mtune-ctrl=^prologue_using_move,^epilogue_using_move" } */
+
+#include "no-callee-saved-1.c"
+
+/* { dg-final { scan-assembler-not "push" } } */
+/* { dg-final { scan-assembler-not "pop" } } */
+/* { dg-final { scan-assembler-times ".cfi_undefined rbx" 1 { target { ! ia32
} } } } */
+/* { dg-final { scan-assembler-times ".cfi_undefined rbp" 1 { target { ! ia32
} } } } */
+/* { dg-final { scan-assembler-times ".cfi_undefined r12" 1 { target { ! ia32
} } } } */
+/* { dg-final { scan-assembler-times ".cfi_undefined r13" 1 { target { ! ia32
} } } } */
+/* { dg-final { scan-assembler-times ".cfi_undefined r14" 1 { target { ! ia32
} } } } */
+/* { dg-final { scan-assembler-times ".cfi_undefined r15" 1 { target { ! ia32
} } } } */
+/* { dg-final { scan-assembler-times ".cfi_undefined ebx" 1 { target ia32 } }
} */
+/* { dg-final { scan-assembler-times ".cfi_undefined esi" 1 { target ia32 } }
} */
+/* { dg-final { scan-assembler-times ".cfi_undefined edi" 1 { target ia32 } }
} */
+/* { dg-final { scan-assembler-times ".cfi_undefined ebp" 1 { target ia32 } }
} */
diff --git a/gcc/testsuite/gcc.target/i386/no-callee-saved-20.c
b/gcc/testsuite/gcc.target/i386/no-callee-saved-20.c
new file mode 100644
index 00000000000..fc94778824a
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/no-callee-saved-20.c
@@ -0,0 +1,12 @@
+/* { dg-do compile { target cfi } } */
+/* { dg-options "-march=tigerlake -O2
-mtune-ctrl=^prologue_using_move,^epilogue_using_move" } */
+
+__attribute__ ((no_callee_saved_registers))
+void
+foo (void)
+{
+}
+
+/* { dg-final { scan-assembler-not "push" } } */
+/* { dg-final { scan-assembler-not "pop" } } */
+/* { dg-final { scan-assembler-not ".cfi_undefined" } } */
diff --git a/gcc/testsuite/gcc.target/i386/pr38534-7.c
b/gcc/testsuite/gcc.target/i386/pr38534-7.c
new file mode 100644
index 00000000000..01dbd77cd75
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr38534-7.c
@@ -0,0 +1,18 @@
+/* { dg-do assemble { target *-*-linux* *-*-gnu* } } */
+/* { dg-options "-save-temps -march=tigerlake -O2
-mtune-ctrl=^prologue_using_move,^epilogue_using_move" } */
+
+#include "pr38534-1.c"
+
+/* { dg-final { scan-assembler-not "push" } } */
+/* { dg-final { scan-assembler-not "pop" } } */
+/* { dg-final { scan-assembler-times ".cfi_undefined rbx" 1 { target { ! ia32
} } } } */
+/* { dg-final { scan-assembler-times ".cfi_undefined rbp" 1 { target { ! ia32
} } } } */
+/* { dg-final { scan-assembler-times ".cfi_undefined r12" 1 { target { ! ia32
} } } } */
+/* { dg-final { scan-assembler-times ".cfi_undefined r13" 1 { target { ! ia32
} } } } */
+/* { dg-final { scan-assembler-times ".cfi_undefined r14" 1 { target { ! ia32
} } } } */
+/* { dg-final { scan-assembler-times ".cfi_undefined r15" 1 { target lp64 } }
} */
+/* { dg-final { scan-assembler-not ".cfi_undefined r15" { target x32 } } } */
+/* { dg-final { scan-assembler-times ".cfi_undefined ebx" 1 { target ia32 } }
} */
+/* { dg-final { scan-assembler-times ".cfi_undefined esi" 1 { target ia32 } }
} */
+/* { dg-final { scan-assembler-times ".cfi_undefined edi" 1 { target ia32 } }
} */
+/* { dg-final { scan-assembler-times ".cfi_undefined ebp" 1 { target ia32 } }
} */
diff --git a/gcc/testsuite/gcc.target/i386/pr38534-8.c
b/gcc/testsuite/gcc.target/i386/pr38534-8.c
new file mode 100644
index 00000000000..020c1512db1
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr38534-8.c
@@ -0,0 +1,13 @@
+/* { dg-do compile { target cfi } } */
+/* { dg-options "-march=tigerlake -O2
-mtune-ctrl=^prologue_using_move,^epilogue_using_move" } */
+
+void
+__attribute__((noreturn))
+no_return_to_caller (void)
+{
+ while (1);
+}
+
+/* { dg-final { scan-assembler-not "push" } } */
+/* { dg-final { scan-assembler-not "pop" } } */
+/* { dg-final { scan-assembler-not ".cfi_undefined" } } */
--
2.43.0
