[PATCH, i386]: Cleanup TARGET_GNU2_TLS usage

[Uros Bizjak <ubizjak at gmail dot com>]

Hello!

Attached patch cleans legitimize_tls_address and corresponding
expanders to call gen_tls_dynamic_gnu2_{32,64} directly in case of
TARGET_GNU2_TLS target. The patch also changes unique REG_EQUIV note
to __tls_get_addr call to UNSPEC (the same approach MIPS does) instead
of some strange nested EXPR_LISTs. Additionally, ix86_tls_get_address
is now used only in i386.c, so it can be declared static.

The patch does not introduce any functional change, leaving also
previous ICE on 64bit targets with -mcmodel=large and
-mtls-dialect=gnu:

tls.c:6:1: error: unrecognizable insn:
(call_insn/u 5 4 6 3 (parallel [
            (set (reg:DI 0 ax)
                (call:DI (mem:QI (symbol_ref:DI ("__tls_get_addr")) [0 S1 A8])
                    (const_int 0 [0])))
            (unspec:DI [
                    (symbol_ref:DI ("tls_gd") [flags 0x12] <var_decl
0x7f3846c08000 tls_gd>)
                ] UNSPEC_TLS_GD)
        ]) tls.c:5 -1
     (expr_list:REG_EH_REGION (const_int -2147483648 [0xffffffff80000000])
        (nil))
    (nil))

The test (tls.c), used to check all TLS models is attached to the
message. I plan to convert it to proper dg test... ;)

2011-05-11  Uros Bizjak  <ubizjak@gmail.com>

	* config/i386/i386.c (legitimize_tls_address)
	<TLS_MODEL_GLOBAL_DYNAMIC>: Call gen_tls_dynamic_gnu2_{32,64}
	expanders directly for TARGET_GNU2_TLS.  Determine pic and
	__tls_get_addr symbol reference here.  Update call to
	gen_tls_global_dynamic_{32,64} for added arguments.
	<TLS_MODEL_LOCAL_DYNAMIC>: Call gen_tls_dynamic_gnu2_{32,64}
	expanders directly for TARGET_GNU2_TLS.  Determine
	__tls_get_addr symbol reference here.  Update call to
	gen_tls_local_dynamic_base_{32,64} for added arguments.  Attach
	unique UNSPEC REG_EQUIV to libcall block.
	(ix86_tls_get_addr): Declare static.
	* config/i386/i386-protos.h (ix86_tls_get_addr): Remove declaration.
	* config/i386/i386.md (tls_global_dynamic_32): Add operand 2 and 3.
	Do not determine pic and __tls_get_addr symbol reference here. Do not
	call gen_tls_dynamic_gnu2_32 for TARGET_GNU2_TLS.
	(tls_local_dynamic_base_32): Ditto for operands 1 and 2.
	(tls_global_dynamic_64): Add operand 2.  Do not determine
	__tls_get_addr symbol reference here.  Do not call
	gen_tls_dynamic_gnu2_64 for TARGET_GNU2_TLS here.
	(tls_local_dynamic_base64): Ditto for operand 1.

Patch was tested on x86_64-pc-linux-gnu {,-m32} and committed to mainline SVN.

Uros.

Attachment: p.diff.txt
Description: Text document

__thread int tls_gd __attribute__((tls_model("global-dynamic")));

int get_gd(void)
{
  return tls_gd;
}

int *get_gdp(void)
{
  return &tls_gd;
}

__thread int tls_ld __attribute__((tls_model("local-dynamic")));
__thread int tls_ld2 __attribute__((tls_model("local-dynamic")));

int get_ld(void)
{
  return tls_ld + tls_ld2;
}

int *get_ldp(void)
{
  return &tls_ld;
}

__thread int tls_le __attribute__((tls_model("local-exec")));

int get_le(void)
{
  return tls_le;
}

int *get_lep(void)
{
  return &tls_le;
}

__thread int tls_ie __attribute__((tls_model("initial-exec")));

int get_ie(void)
{
  return tls_ie;
}

int *get_iep(void)
{
  return &tls_ie;
}