https://gcc.gnu.org/g:afd88fad1615032b5bea2a1916757eee6edaeac9
commit r15-10226-gafd88fad1615032b5bea2a1916757eee6edaeac9
Author: H.J. Lu <hjl.to...@gmail.com>
Date: Thu Jul 24 07:38:13 2025 -0700
x86: Disallow -mtls-dialect=gnu with no_caller_saved_registers
__tls_get_addr doesn't preserve vector registers. When a function
with no_caller_saved_registers attribute calls __tls_get_addr, YMM
and ZMM registers will be clobbered. Issue an error and suggest
-mtls-dialect=gnu2 in this case.
gcc/
PR target/121208
* config/i386/i386.cc (ix86_tls_get_addr): Issue an error for
-mtls-dialect=gnu with no_caller_saved_registers attribute and
suggest -mtls-dialect=gnu2.
gcc/testsuite/
PR target/121208
* gcc.target/i386/pr121208-1a.c: New test.
* gcc.target/i386/pr121208-1b.c: Likewise.
* gcc.target/i386/pr121208-2a.c: Likewise.
* gcc.target/i386/pr121208-2b.c: Likewise.
* gcc.target/i386/pr121208-3a.c: Likewise.
* gcc.target/i386/pr121208-3b.c: Likewise.
Signed-off-by: H.J. Lu <hjl.to...@gmail.com>
(cherry picked from commit 5760ddbce26ff9c5c8851b6b2089ad65981d5078)
Diff:
---
gcc/config/i386/i386.cc | 22 ++++++++++++++++++++++
gcc/testsuite/gcc.target/i386/pr121208-1a.c | 15 +++++++++++++++
gcc/testsuite/gcc.target/i386/pr121208-1b.c | 4 ++++
gcc/testsuite/gcc.target/i386/pr121208-2a.c | 17 +++++++++++++++++
gcc/testsuite/gcc.target/i386/pr121208-2b.c | 4 ++++
gcc/testsuite/gcc.target/i386/pr121208-3a.c | 17 +++++++++++++++++
gcc/testsuite/gcc.target/i386/pr121208-3b.c | 4 ++++
7 files changed, 83 insertions(+)
diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
index 08d0519ccd13..b481f0161f55 100644
--- a/gcc/config/i386/i386.cc
+++ b/gcc/config/i386/i386.cc
@@ -12132,6 +12132,28 @@ static GTY(()) rtx ix86_tls_symbol;
static rtx
ix86_tls_get_addr (void)
{
+ if (cfun->machine->call_saved_registers
+ == TYPE_NO_CALLER_SAVED_REGISTERS)
+ {
+ /* __tls_get_addr doesn't preserve vector registers. When a
+ function with no_caller_saved_registers attribute calls
+ __tls_get_addr, YMM and ZMM registers will be clobbered.
+ Issue an error and suggest -mtls-dialect=gnu2 in this case. */
+ if (cfun->machine->func_type == TYPE_NORMAL)
+ error (G_("%<-mtls-dialect=gnu2%> must be used with a function"
+ " with the %<no_caller_saved_registers%> attribute"));
+ else
+ error (cfun->machine->func_type == TYPE_EXCEPTION
+ ? G_("%<-mtls-dialect=gnu2%> must be used with an"
+ " exception service routine")
+ : G_("%<-mtls-dialect=gnu2%> must be used with an"
+ " interrupt service routine"));
+ /* Don't issue the same error twice. */
+ cfun->machine->func_type = TYPE_NORMAL;
+ cfun->machine->call_saved_registers
+ = TYPE_DEFAULT_CALL_SAVED_REGISTERS;
+ }
+
if (!ix86_tls_symbol)
{
const char *sym
diff --git a/gcc/testsuite/gcc.target/i386/pr121208-1a.c
b/gcc/testsuite/gcc.target/i386/pr121208-1a.c
new file mode 100644
index 000000000000..ac851cb50d86
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr121208-1a.c
@@ -0,0 +1,15 @@
+/* { dg-do compile { target *-*-linux* } } */
+/* { dg-options "-O2 -fPIC -mtls-dialect=gnu" } */
+
+extern __thread int bar;
+extern void func (void);
+
+__attribute__((no_caller_saved_registers))
+void
+foo (int error)
+{
+ bar = 1; /* { dg-error -mtls-dialect=gnu2 } */
+ if (error == 0)
+ func ();
+ bar = 0;
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr121208-1b.c
b/gcc/testsuite/gcc.target/i386/pr121208-1b.c
new file mode 100644
index 000000000000..b97ac715c655
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr121208-1b.c
@@ -0,0 +1,4 @@
+/* { dg-do compile { target *-*-linux* } } */
+/* { dg-options "-O2 -fPIC -mtls-dialect=gnu2" } */
+
+#include "pr121208-1a.c"
diff --git a/gcc/testsuite/gcc.target/i386/pr121208-2a.c
b/gcc/testsuite/gcc.target/i386/pr121208-2a.c
new file mode 100644
index 000000000000..c1891ae322c6
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr121208-2a.c
@@ -0,0 +1,17 @@
+/* { dg-do compile { target *-*-linux* } } */
+/* { dg-options "-O2 -fPIC -mtls-dialect=gnu" } */
+
+typedef unsigned int uword_t __attribute__ ((mode (__word__)));
+extern __thread int bar;
+extern void func (void);
+
+__attribute__((target("general-regs-only")))
+__attribute__((interrupt))
+void
+foo (void *frame, uword_t error)
+{
+ bar = 1; /* { dg-error -mtls-dialect=gnu2 } */
+ if (error == 0)
+ func ();
+ bar = 0;
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr121208-2b.c
b/gcc/testsuite/gcc.target/i386/pr121208-2b.c
new file mode 100644
index 000000000000..269b120f9906
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr121208-2b.c
@@ -0,0 +1,4 @@
+/* { dg-do compile { target *-*-linux* } } */
+/* { dg-options "-O2 -fPIC -mtls-dialect=gnu2" } */
+
+#include "pr121208-2a.c"
diff --git a/gcc/testsuite/gcc.target/i386/pr121208-3a.c
b/gcc/testsuite/gcc.target/i386/pr121208-3a.c
new file mode 100644
index 000000000000..26fe68701559
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr121208-3a.c
@@ -0,0 +1,17 @@
+/* { dg-do compile { target *-*-linux* } } */
+/* { dg-options "-O2 -fPIC -mtls-dialect=gnu" } */
+
+typedef unsigned int uword_t __attribute__ ((mode (__word__)));
+extern __thread int bar;
+extern void func (void);
+
+__attribute__((target("general-regs-only")))
+__attribute__((interrupt))
+void
+foo (void *frame)
+{
+ bar = 1; /* { dg-error -mtls-dialect=gnu2 } */
+ if (frame == 0)
+ func ();
+ bar = 0;
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr121208-3b.c
b/gcc/testsuite/gcc.target/i386/pr121208-3b.c
new file mode 100644
index 000000000000..b672d751d7f6
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr121208-3b.c
@@ -0,0 +1,4 @@
+/* { dg-do compile { target *-*-linux* } } */
+/* { dg-options "-O2 -fPIC -mtls-dialect=gnu2" } */
+
+#include "pr121208-3a.c"
