Save callee-saved registers in noreturn functions for -O0/-Og so that
debugger can restore callee-saved registers in caller's frame.
gcc/
PR target/38534
* config/i386/i386-options.cc (ix86_set_func_type): Save
callee-saved registers in noreturn functions for -O0/-Og.
gcc/testsuite/
PR target/38534
* gcc.target/i386/pr38534-5.c: New file.
* gcc.target/i386/pr38534-6.c: Likewise.
---
gcc/config/i386/i386-options.cc | 7 ++++--
gcc/testsuite/gcc.target/i386/pr38534-5.c | 26 +++++++++++++++++++++++
gcc/testsuite/gcc.target/i386/pr38534-6.c | 26 +++++++++++++++++++++++
3 files changed, 57 insertions(+), 2 deletions(-)
create mode 100644 gcc/testsuite/gcc.target/i386/pr38534-5.c
create mode 100644 gcc/testsuite/gcc.target/i386/pr38534-6.c
diff --git a/gcc/config/i386/i386-options.cc b/gcc/config/i386/i386-options.cc
index 473f5359fc9..5ff5560df7a 100644
--- a/gcc/config/i386/i386-options.cc
+++ b/gcc/config/i386/i386-options.cc
@@ -3381,7 +3381,8 @@ static void
ix86_set_func_type (tree fndecl)
{
/* No need to save and restore callee-saved registers for a noreturn
- function with nothrow or compiled with -fno-exceptions.
+ function with nothrow or compiled with -fno-exceptions unless when
+ compiling with -O0 or -Og.
NB: Don't use TREE_THIS_VOLATILE to check if this is a noreturn
function. The local-pure-const pass turns an interrupt function
@@ -3391,7 +3392,9 @@ ix86_set_func_type (tree fndecl)
function is marked as noreturn in the IR output, which leads the
incompatible attribute error in LTO1. */
bool has_no_callee_saved_registers
- = (((TREE_NOTHROW (fndecl) || !flag_exceptions)
+ = ((optimize
+ && !optimize_debug
+ && (TREE_NOTHROW (fndecl) || !flag_exceptions)
&& lookup_attribute ("noreturn", DECL_ATTRIBUTES (fndecl)))
|| lookup_attribute ("no_callee_saved_registers",
TYPE_ATTRIBUTES (TREE_TYPE (fndecl))));
diff --git a/gcc/testsuite/gcc.target/i386/pr38534-5.c
b/gcc/testsuite/gcc.target/i386/pr38534-5.c
new file mode 100644
index 00000000000..91c0c0f8c59
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr38534-5.c
@@ -0,0 +1,26 @@
+/* { dg-do compile } */
+/* { dg-options "-O0 -mtune-ctrl=^prologue_using_move,^epilogue_using_move" }
*/
+
+#define ARRAY_SIZE 256
+
+extern int array[ARRAY_SIZE][ARRAY_SIZE][ARRAY_SIZE];
+extern int value (int, int, int)
+#ifndef __x86_64__
+__attribute__ ((regparm(3)))
+#endif
+;
+
+void
+__attribute__((noreturn))
+no_return_to_caller (void)
+{
+ unsigned i, j, k;
+ for (i = ARRAY_SIZE; i > 0; --i)
+ for (j = ARRAY_SIZE; j > 0; --j)
+ for (k = ARRAY_SIZE; k > 0; --k)
+ array[i - 1][j - 1][k - 1] = value (i, j, k);
+ while (1);
+}
+
+/* { dg-final { scan-assembler "push" } } */
+/* { dg-final { scan-assembler-not "pop" } } */
diff --git a/gcc/testsuite/gcc.target/i386/pr38534-6.c
b/gcc/testsuite/gcc.target/i386/pr38534-6.c
new file mode 100644
index 00000000000..756e1ec81f5
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr38534-6.c
@@ -0,0 +1,26 @@
+/* { dg-do compile } */
+/* { dg-options "-Og -mtune-ctrl=^prologue_using_move,^epilogue_using_move" }
*/
+
+#define ARRAY_SIZE 256
+
+extern int array[ARRAY_SIZE][ARRAY_SIZE][ARRAY_SIZE];
+extern int value (int, int, int)
+#ifndef __x86_64__
+__attribute__ ((regparm(3)))
+#endif
+;
+
+void
+__attribute__((noreturn))
+no_return_to_caller (void)
+{
+ unsigned i, j, k;
+ for (i = ARRAY_SIZE; i > 0; --i)
+ for (j = ARRAY_SIZE; j > 0; --j)
+ for (k = ARRAY_SIZE; k > 0; --k)
+ array[i - 1][j - 1][k - 1] = value (i, j, k);
+ while (1);
+}
+
+/* { dg-final { scan-assembler "push" } } */
+/* { dg-final { scan-assembler-not "pop" } } */
--
2.43.0
