[gcc r12-9479] x86: Disable -mforce-indirect-call for PIC in 32-bit mode

[gcc r12-9479] x86: Disable -mforce-indirect-call for PIC in 32-bit mode

[Richard Biener]

https://gcc.gnu.org/g:37da428922e5cb548430aa00482d6a4c7aa8f8b2

commit r12-9479-g37da428922e5cb548430aa00482d6a4c7aa8f8b2
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Mon Jan 16 10:45:41 2023 -0800

    x86: Disable -mforce-indirect-call for PIC in 32-bit mode
    
    -mforce-indirect-call generates invalid instruction in 32-bit MI thunk
    since there are no available scratch registers in 32-bit PIC mode.
    Disable -mforce-indirect-call for PIC in 32-bit mode when generating
    MI thunk.
    
    gcc/
    
            PR target/105980
            * config/i386/i386.cc (x86_output_mi_thunk): Disable
            -mforce-indirect-call for PIC in 32-bit mode.
    
    gcc/testsuite/
    
            PR target/105980
            * g++.target/i386/pr105980.C: New test.
    
    (cherry picked from commit a396a123596d82d4a2f14dc43a382cb17826411c)

Diff:
---
 gcc/config/i386/i386.cc                  | 6 ++++++
 gcc/testsuite/g++.target/i386/pr105980.C | 8 ++++++++
 2 files changed, 14 insertions(+)

diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
index 85402f851bf..9a9ff3b34b8 100644
--- a/gcc/config/i386/i386.cc
+++ b/gcc/config/i386/i386.cc
@@ -21211,6 +21211,7 @@ x86_output_mi_thunk (FILE *file, tree thunk_fndecl, HOST_WIDE_INT delta,
   rtx this_reg, tmp, fnaddr;
   unsigned int tmp_regno;
   rtx_insn *insn;
+  int saved_flag_force_indirect_call = flag_force_indirect_call;
 
   if (TARGET_64BIT)
     tmp_regno = R10_REG;
@@ -21223,6 +21224,9 @@ x86_output_mi_thunk (FILE *file, tree thunk_fndecl, HOST_WIDE_INT delta,
 	tmp_regno = DX_REG;
       else
 	tmp_regno = CX_REG;
+
+      if (flag_pic)
+  flag_force_indirect_call = 0;
     }
 
   emit_note (NOTE_INSN_PROLOGUE_END);
@@ -21390,6 +21394,8 @@ x86_output_mi_thunk (FILE *file, tree thunk_fndecl, HOST_WIDE_INT delta,
   final (insn, file, 1);
   final_end_function ();
   assemble_end_function (thunk_fndecl, fnname);
+
+  flag_force_indirect_call = saved_flag_force_indirect_call;
 }
 
 static void
diff --git a/gcc/testsuite/g++.target/i386/pr105980.C b/gcc/testsuite/g++.target/i386/pr105980.C
new file mode 100644
index 00000000000..d8dbc332ea2
--- /dev/null
+++ b/gcc/testsuite/g++.target/i386/pr105980.C
@@ -0,0 +1,8 @@
+// { dg-do assemble { target { fpic } } }
+// { dg-options "-O0 -fpic -mforce-indirect-call" }
+
+struct A {
+  virtual ~A();
+};
+struct B : virtual A {};
+void bar() { B(); }