[gcc r14-9411] LoongArch: Emit R_LARCH_RELAX for TLS IE with non-extreme code model to allow the IE to LE linker re

[Xi Ruoyao <xry111@gcc.gnu.org>]

https://gcc.gnu.org/g:42cd49aa48c7ca99e8d5e91ce582d41fdb75f3fc

commit r14-9411-g42cd49aa48c7ca99e8d5e91ce582d41fdb75f3fc
Author: Xi Ruoyao <xry111@xry111.site>
Date:   Fri Jan 26 18:28:32 2024 +0800

    LoongArch: Emit R_LARCH_RELAX for TLS IE with non-extreme code model to allow the IE to LE linker relaxation
    
    In Binutils we need to make IE to LE relaxation only allowed when there
    is an R_LARCH_RELAX after R_LARCH_TLE_IE_PC_{HI20,LO12} so an invalid
    "partial" relaxation won't happen with the extreme code model.  So if we
    are emitting %ie_pc_{hi20,lo12} in a non-extreme code model, emit an
    R_LARCH_RELAX to allow the relaxation.  The IE to LE relaxation does not
    require the pcalau12i and the ld instruction to be adjacent, so we don't
    need to limit ourselves to use the macro.
    
    For the distro maintainers backporting changes: this change depends on
    r14-8721, without r14-8721 R_LARCH_RELAX can be emitted mistakenly in
    the extreme code model.
    
    gcc/ChangeLog:
    
            * config/loongarch/loongarch.cc (loongarch_print_operand_reloc):
            Support 'Q' for R_LARCH_RELAX for TLS IE.
            (loongarch_output_move): Use 'Q' to print R_LARCH_RELAX for TLS
            IE.
            * config/loongarch/loongarch.md (ld_from_got<mode>): Likewise.
    
    gcc/testsuite/ChangeLog:
    
            * gcc.target/loongarch/tls-ie-relax.c: New test.
            * gcc.target/loongarch/tls-ie-norelax.c: New test.
            * gcc.target/loongarch/tls-ie-extreme.c: New test.

Diff:
---
 gcc/config/loongarch/loongarch.cc                   | 15 ++++++++++++++-
 gcc/config/loongarch/loongarch.md                   |  2 +-
 gcc/testsuite/gcc.target/loongarch/tls-ie-extreme.c |  5 +++++
 gcc/testsuite/gcc.target/loongarch/tls-ie-norelax.c |  5 +++++
 gcc/testsuite/gcc.target/loongarch/tls-ie-relax.c   | 11 +++++++++++
 5 files changed, 36 insertions(+), 2 deletions(-)

diff --git a/gcc/config/loongarch/loongarch.cc b/gcc/config/loongarch/loongarch.cc
index 0428b6e65d5..70e31bb831c 100644
--- a/gcc/config/loongarch/loongarch.cc
+++ b/gcc/config/loongarch/loongarch.cc
@@ -4981,7 +4981,7 @@ loongarch_output_move (rtx dest, rtx src)
 	  if (type == SYMBOL_TLS_LE)
 	    return "lu12i.w\t%0,%h1";
 	  else
-	    return "pcalau12i\t%0,%h1";
+	    return "%Q1pcalau12i\t%0,%h1";
 	}
 
       if (src_code == CONST_INT)
@@ -6145,6 +6145,7 @@ loongarch_print_operand_reloc (FILE *file, rtx op, bool hi64_part,
    'L'  Print the low-part relocation associated with OP.
    'm'	Print one less than CONST_INT OP in decimal.
    'N'	Print the inverse of the integer branch condition for comparison OP.
+   'Q'  Print R_LARCH_RELAX for TLS IE.
    'r'  Print address 12-31bit relocation associated with OP.
    'R'  Print address 32-51bit relocation associated with OP.
    'T'	Print 'f' for (eq:CC ...), 't' for (ne:CC ...),
@@ -6282,6 +6283,18 @@ loongarch_print_operand (FILE *file, rtx op, int letter)
 					    letter);
       break;
 
+    case 'Q':
+      if (!TARGET_LINKER_RELAXATION)
+	break;
+
+      if (code == HIGH)
+	op = XEXP (op, 0);
+
+      if (loongarch_classify_symbolic_expression (op) == SYMBOL_TLS_IE)
+	fprintf (file, ".reloc\t.,R_LARCH_RELAX\n\t");
+
+      break;
+
     case 'r':
       loongarch_print_operand_reloc (file, op, false /* hi64_part */,
 				     true /* lo_reloc */);
diff --git a/gcc/config/loongarch/loongarch.md b/gcc/config/loongarch/loongarch.md
index f3b5c641fce..525e1e82183 100644
--- a/gcc/config/loongarch/loongarch.md
+++ b/gcc/config/loongarch/loongarch.md
@@ -2620,7 +2620,7 @@
 				(match_operand:P 2 "symbolic_operand")))]
 	UNSPEC_LOAD_FROM_GOT))]
   ""
-  "ld.<d>\t%0,%1,%L2"
+  "%Q2ld.<d>\t%0,%1,%L2"
   [(set_attr "type" "move")]
 )
 
diff --git a/gcc/testsuite/gcc.target/loongarch/tls-ie-extreme.c b/gcc/testsuite/gcc.target/loongarch/tls-ie-extreme.c
new file mode 100644
index 00000000000..00c545a3e8c
--- /dev/null
+++ b/gcc/testsuite/gcc.target/loongarch/tls-ie-extreme.c
@@ -0,0 +1,5 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -march=loongarch64 -mabi=lp64d -mcmodel=extreme -mexplicit-relocs=auto -mrelax" } */
+/* { dg-final { scan-assembler-not "R_LARCH_RELAX" { target tls_native } } } */
+
+#include "tls-ie-relax.c"
diff --git a/gcc/testsuite/gcc.target/loongarch/tls-ie-norelax.c b/gcc/testsuite/gcc.target/loongarch/tls-ie-norelax.c
new file mode 100644
index 00000000000..dd6bf3634a4
--- /dev/null
+++ b/gcc/testsuite/gcc.target/loongarch/tls-ie-norelax.c
@@ -0,0 +1,5 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mcmodel=normal -mexplicit-relocs -mno-relax" } */
+/* { dg-final { scan-assembler-not "R_LARCH_RELAX" { target tls_native } } } */
+
+#include "tls-ie-relax.c"
diff --git a/gcc/testsuite/gcc.target/loongarch/tls-ie-relax.c b/gcc/testsuite/gcc.target/loongarch/tls-ie-relax.c
new file mode 100644
index 00000000000..e9f7569b1da
--- /dev/null
+++ b/gcc/testsuite/gcc.target/loongarch/tls-ie-relax.c
@@ -0,0 +1,11 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mcmodel=normal -mexplicit-relocs -mrelax" } */
+/* { dg-final { scan-assembler-times "R_LARCH_RELAX" 2 { target tls_native } } } */
+
+extern __thread int errno;
+
+void
+unimplemented (void)
+{
+  errno = -38;
+}