[PATCH] x86-64: Add RDI clobber to tls_global_dynamic_64 patterns

[H.J. Lu]

*tls_global_dynamic_64_<mode> uses RDI as the __tls_get_addr argument.
Add RDI clobber to tls_global_dynamic_64 patterns to show it.

PR target/120908
* config/i386/i386.cc (legitimize_tls_address): Pass RDI to
gen_tls_global_dynamic_64.
* config/i386/i386.md (*tls_global_dynamic_64_<mode>): Add RDI
clobber and use it to generate LEA.
(@tls_global_dynamic_64_<mode>): Add a clobber.

OK for master?

Thanks.

-- 
H.J.

From fb6b52e78caf70b2e3f9939952bda0604295cfce Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.to...@gmail.com>
Date: Tue, 1 Jul 2025 17:17:06 +0800
Subject: [PATCH] x86-64: Add RDI clobber to tls_global_dynamic_64 patterns

*tls_global_dynamic_64_<mode> uses RDI as the __tls_get_addr argument.
Add RDI clobber to tls_global_dynamic_64 patterns to show it.

	PR target/120908
	* config/i386/i386.cc (legitimize_tls_address): Pass RDI to
	gen_tls_global_dynamic_64.
	* config/i386/i386.md (*tls_global_dynamic_64_<mode>): Add RDI
	clobber and use it to generate LEA.
	(@tls_global_dynamic_64_<mode>): Add a clobber.

Signed-off-by: H.J. Lu <hjl.to...@gmail.com>
---
 gcc/config/i386/i386.cc | 3 ++-
 gcc/config/i386/i386.md | 8 +++++---
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
index 44763c8eb01..9657c6ae31f 100644
--- a/gcc/config/i386/i386.cc
+++ b/gcc/config/i386/i386.cc
@@ -12562,11 +12562,12 @@ legitimize_tls_address (rtx x, enum tls_model model, bool for_mov)
 	  if (TARGET_64BIT)
 	    {
 	      rtx rax = gen_rtx_REG (Pmode, AX_REG);
+	      rtx rdi = gen_rtx_REG (Pmode, DI_REG);
 	      rtx_insn *insns;
 
 	      start_sequence ();
 	      emit_call_insn
-		(gen_tls_global_dynamic_64 (Pmode, rax, x, caddr));
+		(gen_tls_global_dynamic_64 (Pmode, rax, x, caddr, rdi));
 	      insns = end_sequence ();
 
 	      if (GET_MODE (x) != Pmode)
diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index adff2af4563..370e79bb511 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -23201,7 +23201,8 @@ (define_insn "*tls_global_dynamic_64_<mode>"
 	 (match_operand 3)))
    (unspec:P [(match_operand 1 "tls_symbolic_operand")
 	      (reg:P SP_REG)]
-	     UNSPEC_TLS_GD)]
+	     UNSPEC_TLS_GD)
+   (clobber (match_operand:P 4 "register_operand" "=D"))]
   "TARGET_64BIT"
 {
   if (!TARGET_X32)
@@ -23218,7 +23219,7 @@ (define_insn "*tls_global_dynamic_64_<mode>"
        Use data16 prefix instead, which doesn't have this problem.  */
     fputs ("\tdata16", asm_out_file);
   output_asm_insn
-    ("lea{q}\t{%E1@tlsgd(%%rip), %%rdi|rdi, %E1@tlsgd[rip]}", operands);
+    ("lea{q}\t{%E1@tlsgd(%%rip), %q4|%q4, %E1@tlsgd[rip]}", operands);
   if (TARGET_SUN_TLS || flag_plt || !HAVE_AS_IX86_TLS_GET_ADDR_GOT)
     fputs (ASM_SHORT "0x6666\n", asm_out_file);
   else
@@ -23265,7 +23266,8 @@ (define_expand "@tls_global_dynamic_64_<mode>"
 	   (const_int 0)))
      (unspec:P [(match_operand 1 "tls_symbolic_operand")
 		(reg:P SP_REG)]
-	       UNSPEC_TLS_GD)])]
+	       UNSPEC_TLS_GD)
+     (clobber (match_operand:P 3 "register_operand"))])]
   "TARGET_64BIT"
   "ix86_tls_descriptor_calls_expanded_in_cfun = true;")
 
-- 
2.50.0