AVR: ipa/92606 - Don't optimize PROGMEM data against non-PROGMEM.

ipa/92606: Inter-procedural analysis optimizes data across
address-spaces and PROGMEM.  As of v14, the PROGMEM part is
still not fixed (and there is still no target hook as proposed
in PR92932).  Just disable respective bogus optimization.

	PR ipa/92606
gcc/
	* config/avr/avr.cc (avr_option_override): Set
	flag_ipa_icf_variables = 0.
gcc/testsuite/
	* gcc.target/avr/torture/pr92606.c: New test.

(cherry picked from commit 08e752e)

Author: sprintersb

gcc/config/avr/avr.cc

@@ -1112,6 +1112,12 @@ avr_option_override (void)
   if (targetm.addr_space.zero_address_valid (ADDR_SPACE_GENERIC))
     flag_delete_null_pointer_checks = 0;
 
+  /* PR ipa/92606: Inter-procedural analysis optimizes data across
+     address-spaces and PROGMEM.  As of v14, the PROGMEM part is
+     still not fixed (and there is still no target hook as proposed
+     in PR92932).  Just disable respective bogus optimization.  */
+  flag_ipa_icf_variables = 0;
+
   if (flag_pic == 1)
     warning (OPT_fpic, "%<-fpic%> is not supported");
   if (flag_pic == 2)

gcc/testsuite/gcc.target/avr/torture/pr92606.c

@@ -0,0 +1,57 @@
+/* { dg-do run } */
+
+typedef __UINT16_TYPE__ uint16_t;
+typedef __UINT32_TYPE__ uint32_t;
+
+typedef uint32_t T;
+
+#define NI __attribute__((noinline,noclone))
+
+
+#ifndef __AVR_TINY__
+#define read_u32(X)                                                     \
+    (__extension__(                                                     \
+        {                                                               \
+            uint16_t __addr16 = (uint16_t)(X);                          \
+            uint32_t __result;                                          \
+            __asm__ __volatile__ ("lpm %A0, Z+" "\n\t"                  \
+                                  "lpm %B0, Z+" "\n\t"                  \
+                                  "lpm %C0, Z+" "\n\t"                  \
+                                  "lpm %D0, Z" "\n\t"                   \
+                                  : "=r" (__result), "+z" (__addr16));  \
+            __result;                                                   \
+        }))
+#else
+NI uint32_t read_u32 (const uint32_t *p)
+{
+	return *p;
+}
+#endif
+
+static const __attribute((progmem)) T xyz_prog[] = { 123, 123, 123 };
+T xyz[] = { 123, 123, 123 };
+volatile int x = 0;
+
+NI void prf (T f)
+{
+    if (f != 123)
+        __builtin_abort();
+}
+
+NI void func_progmem()
+{
+    prf (read_u32 (&xyz_prog[0]));
+}
+
+NI void func_ram()
+{
+    prf (xyz[x]);
+}
+
+int main (void)
+{
+    func_progmem();
+    func_ram();
+
+	return 0;
+}