Use a GOT indirection for extern weak symbols instead of a literal - this is
the same as
PIC/PIE and mirrors LLVM behaviour. Ensure PIC/PIE use the same offset limits
for symbols
that don't use the GOT.
Passes bootstrap and regress. OK for commit?
ChangeLog:
2021-04-27 Wilco Dijkstra <wdijk...@arm.com>
* config/aarch64/aarch64.c (aarch64_classify_symbol): Use GOT for
extern weak symbols.
Limit symbol offsets for non-GOT symbols with PIC/PIE.
---
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index
82957dddbe42a7f907b2960294ac7f8abf7be2ff..08aaea70d952fd62147b7f06ba781eb55e697d3a
100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -17854,7 +17854,12 @@ aarch64_classify_symbol (rtx x, HOST_WIDE_INT offset)
switch (aarch64_cmodel)
{
+ case AARCH64_CMODEL_TINY_PIC:
case AARCH64_CMODEL_TINY:
+ if ((flag_pic || SYMBOL_REF_WEAK (x))
+ && !aarch64_symbol_binds_local_p (x))
+ return SYMBOL_TINY_GOT;
+
/* When we retrieve symbol + offset address, we have to make sure
the offset does not cause overflow of the final address. But
we have no way of knowing the address of symbol at compile time
@@ -17865,39 +17870,29 @@ aarch64_classify_symbol (rtx x, HOST_WIDE_INT offset)
If offset_within_block_p is true we allow larger offsets.
Furthermore force to memory if the symbol is a weak reference to
something that doesn't resolve to a symbol in this module. */
-
- if (SYMBOL_REF_WEAK (x) && !aarch64_symbol_binds_local_p (x))
- return SYMBOL_FORCE_TO_MEM;
if (!(IN_RANGE (offset, -0x10000, 0x10000)
|| offset_within_block_p (x, offset)))
return SYMBOL_FORCE_TO_MEM;
return SYMBOL_TINY_ABSOLUTE;
+
+ case AARCH64_CMODEL_SMALL_SPIC:
+ case AARCH64_CMODEL_SMALL_PIC:
case AARCH64_CMODEL_SMALL:
+ if ((flag_pic || SYMBOL_REF_WEAK (x))
+ && !aarch64_symbol_binds_local_p (x))
+ return aarch64_cmodel == AARCH64_CMODEL_SMALL_SPIC
+ ? SYMBOL_SMALL_GOT_28K : SYMBOL_SMALL_GOT_4G;
+
/* Same reasoning as the tiny code model, but the offset cap here is
1MB, allowing +/-3.9GB for the offset to the symbol. */
-
- if (SYMBOL_REF_WEAK (x) && !aarch64_symbol_binds_local_p (x))
- return SYMBOL_FORCE_TO_MEM;
if (!(IN_RANGE (offset, -0x100000, 0x100000)
|| offset_within_block_p (x, offset)))
return SYMBOL_FORCE_TO_MEM;
return SYMBOL_SMALL_ABSOLUTE;
- case AARCH64_CMODEL_TINY_PIC:
- if (!aarch64_symbol_binds_local_p (x))
- return SYMBOL_TINY_GOT;
- return SYMBOL_TINY_ABSOLUTE;
-
- case AARCH64_CMODEL_SMALL_SPIC:
- case AARCH64_CMODEL_SMALL_PIC:
- if (!aarch64_symbol_binds_local_p (x))
- return (aarch64_cmodel == AARCH64_CMODEL_SMALL_SPIC
- ? SYMBOL_SMALL_GOT_28K : SYMBOL_SMALL_GOT_4G);
- return SYMBOL_SMALL_ABSOLUTE;
-
case AARCH64_CMODEL_LARGE:
/* This is alright even in PIC code as the constant
pool reference is always PC relative and within
