[patch]: Implement PR104327 for avr

[Georg-Johann Lay <avr@gjlay.de>]

PR target/104327 not only affects s390 but also avr:
The avr backend pre-sets some options depending on optimization level.
The inliner then thinks that always_inline functions are not eligible
for inlining and terminates with an error.

Proposing the following patch that implements TARGET_CAN_INLINE_P.

Ok to apply?

Johann

--

target/104327: Allow more inlining between different optimization levels.

avr-common.cc introduces the following options that are set depending
on optimization level: -mgas-isr-prologues, -mmain-is-OS-task and
-fsplit-wide-types-early.  The inliner thinks that different options
disallow cross-optimization inlining, so provide can_inline_p.

gcc/
	PR target/104327
	* config/avr/avr.cc (avr_can_inline_p): New static function.
	(TARGET_CAN_INLINE_P): Define to that function.
diff --git a/gcc/config/avr/avr.cc b/gcc/config/avr/avr.cc
index 9fa50ca230d..55b48f63865 100644
--- a/gcc/config/avr/avr.cc
+++ b/gcc/config/avr/avr.cc
@@ -1018,6 +1018,22 @@ avr_no_gccisr_function_p (tree func)
    return avr_lookup_function_attribute1 (func, "no_gccisr");
  }

+
+/* Implement `TARGET_CAN_INLINE_P'.  */
+/* Some options like -mgas_isr_prologues depend on optimization level,
+   and the inliner might think that due to different options, inlining
+   is not permitted; see PR104327.  */
+
+static bool
+avr_can_inline_p (tree /* caller */, tree callee)
+{
+  // For now, dont't allow to inline ISRs.  If the user actually wants
+  // to inline ISR code, they have to turn the body of the ISR into an
+  // ordinary function.
+
+  return ! avr_interrupt_function_p (callee);
+}
+
  /* Implement `TARGET_SET_CURRENT_FUNCTION'.  */
  /* Sanity cheching for above function attributes.  */

@@ -14713,6 +14729,9 @@ avr_float_lib_compare_returns_bool (machine_mode 
mode, enum rtx_code)
  #undef  TARGET_MD_ASM_ADJUST
  #define TARGET_MD_ASM_ADJUST avr_md_asm_adjust

+#undef  TARGET_CAN_INLINE_P
+#define TARGET_CAN_INLINE_P avr_can_inline_p
+
  struct gcc_target targetm = TARGET_INITIALIZER;

  \f