For the AVR target, assertions in convert_debug_memory_address cause a
couple of ICEs (see PR 52472). Jakub suggested returning a NULL rtx,
which works, but on debugging further, I found that expand_debug_expr
appears to incorrectly compute the address space for ADDR_EXPR and
MEM_REFs.
For ADDR_EXPR, TREE_TYPE(exp) is a POINTER_TYPE (always?), but in
the generic address space, even if the object whose address is taken
is in a different address space. expand_debug_expr takes
TYPE_ADDR_SPACE(TREE_TYPE(exp)) and therefore computes the address
space as generic. convert_debug_memory_address then asserts that the
mode is a valid pointer mode in the address space and fails.
Similarly, for MEM_REFs, TREE_TYPE(exp) is the type of the
dereferenced value, and therefore checking if it is a POINTER_TYPE
doesn't help for a single pointer dereference. The address space
gets computed as generic even if the pointer points to a different
address space. The address mode for the generic address space is
passed to convert_debug_memory_address, and the assertion that that mode
must match the mode of the rtx then fails.
The below patch attempts to fix this by picking the right TREE_TYPE to
pass to TYPE_ADDR_SPACE for MEM_REF (use type of arg 0) and
ADDR_EXPR (check for pointer type and look at nested addr space).
Does this look reasonable or did I get it all wrong?
Regards
Senthil
diff --git gcc/cfgexpand.c gcc/cfgexpand.c
index 8b0e466..ca78953 100644
--- gcc/cfgexpand.c
+++ gcc/cfgexpand.c
@@ -3941,8 +3941,8 @@ expand_debug_expr (tree exp)
op0 = plus_constant (inner_mode, op0, INTVAL (op1));
}
- if (POINTER_TYPE_P (TREE_TYPE (exp)))
- as = TYPE_ADDR_SPACE (TREE_TYPE (TREE_TYPE (exp)));
+ if (POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (exp, 0))))
+ as = TYPE_ADDR_SPACE (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp, 0))));
else
as = ADDR_SPACE_GENERIC;
@@ -4467,7 +4467,11 @@ expand_debug_expr (tree exp)
return NULL;
}
- as = TYPE_ADDR_SPACE (TREE_TYPE (exp));
+ if (POINTER_TYPE_P (TREE_TYPE (exp)))
+ as = TYPE_ADDR_SPACE (TREE_TYPE (TREE_TYPE (exp)));
+ else
+ as = TYPE_ADDR_SPACE (TREE_TYPE (exp));
+
op0 = convert_debug_memory_address (mode, XEXP (op0, 0), as);
return op0;
