Since sibcall never returns, we can only use call-clobbered register
as GOT base. Otherwise, callee-saved register used as GOT base won't
be properly restored.
Tested on x86-64 with -m32. OK for trunk?
H.J.
---
gcc/
PR target/68937
* config/i386/i386.c (ix86_function_ok_for_sibcall): Count
call via GOT slot as indirect call.
(ix86_expand_call): Mark PIC register used for sibcall as
call-clobbered.
* config/i386/i386.md (*sibcall_GOT_32): New pattern.
(*sibcall_value_GOT_32): Likewise.
gcc/testsuite/
PR target/68937
* gcc.target/i386/pr68937-1.c: New test.
* gcc.target/i386/pr68937-2.c: Likewise.
* gcc.target/i386/pr68937-3.c: Likewise.
* gcc.target/i386/pr68937-4.c: Likewise.
---
gcc/config/i386/i386.c | 15 ++++++++---
gcc/config/i386/i386.md | 45 +++++++++++++++++++++++++++++++
gcc/testsuite/gcc.target/i386/pr68937-1.c | 13 +++++++++
gcc/testsuite/gcc.target/i386/pr68937-2.c | 13 +++++++++
gcc/testsuite/gcc.target/i386/pr68937-3.c | 13 +++++++++
gcc/testsuite/gcc.target/i386/pr68937-4.c | 13 +++++++++
6 files changed, 109 insertions(+), 3 deletions(-)
create mode 100644 gcc/testsuite/gcc.target/i386/pr68937-1.c
create mode 100644 gcc/testsuite/gcc.target/i386/pr68937-2.c
create mode 100644 gcc/testsuite/gcc.target/i386/pr68937-3.c
create mode 100644 gcc/testsuite/gcc.target/i386/pr68937-4.c
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index cecea24..ebc9d09 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -6723,8 +6723,10 @@ ix86_function_ok_for_sibcall (tree decl, tree exp)
/* If this call is indirect, we'll need to be able to use a
call-clobbered register for the address of the target function.
Make sure that all such registers are not used for passing
- parameters. Note that DLLIMPORT functions are indirect. */
+ parameters. Note that DLLIMPORT functions and call via GOT
+ slot are indirect. */
if (!decl
+ || (flag_pic && !flag_plt)
|| (TARGET_DLLIMPORT_DECL_ATTRIBUTES && DECL_DLLIMPORT_P (decl)))
{
/* Check if regparm >= 3 since arg_reg_available is set to
@@ -27019,8 +27021,8 @@ ix86_expand_call (rtx retval, rtx fnaddr, rtx callarg1,
rtx callarg2,
rtx pop, bool sibcall)
{
- rtx vec[3];
- rtx use = NULL, call;
+ rtx vec[4];
+ rtx use = NULL, call, clobber = NULL;
unsigned int vec_len = 0;
if (pop == const0_rtx)
@@ -27075,6 +27077,10 @@ ix86_expand_call (rtx retval, rtx fnaddr, rtx callarg1,
fnaddr = gen_rtx_UNSPEC (Pmode, gen_rtvec (1, addr),
UNSPEC_GOT);
fnaddr = gen_rtx_CONST (Pmode, fnaddr);
+ /* Since sibcall never returns, mark PIC register as
+ call-clobbered. */
+ if (sibcall)
+ clobber = pic_offset_table_rtx;
fnaddr = gen_rtx_PLUS (Pmode, pic_offset_table_rtx,
fnaddr);
}
@@ -27151,6 +27157,9 @@ ix86_expand_call (rtx retval, rtx fnaddr, rtx callarg1,
}
vec[vec_len++] = call;
+ if (clobber)
+ vec[vec_len++] = gen_rtx_CLOBBER (VOIDmode, clobber);
+
if (pop)
{
pop = gen_rtx_PLUS (Pmode, stack_pointer_rtx, pop);
diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index 49b2216..65c1534 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -11865,6 +11865,28 @@
"* return ix86_output_call_insn (insn, operands[0]);"
[(set_attr "type" "call")])
+;; Since sibcall never returns, we can only use call-clobbered register
+;; as GOT base.
+(define_insn "*sibcall_GOT_32"
+ [(call (mem:QI
+ (mem:SI (plus:SI
+ (match_operand:SI 0 "register_operand" "U")
+ (const:SI
+ (unspec:SI [(match_operand:SI 1 "symbol_operand")]
+ UNSPEC_GOT)))))
+ (match_operand 2))
+ (clobber (match_dup 0))]
+ "!TARGET_MACHO && !TARGET_64BIT && SIBLING_CALL_P (insn)"
+{
+ rtx fnaddr = gen_rtx_UNSPEC (Pmode, gen_rtvec (1, operands[1]),
+ UNSPEC_GOT);
+ fnaddr = gen_rtx_CONST (Pmode, fnaddr);
+ fnaddr = gen_rtx_PLUS (Pmode, operands[0], fnaddr);
+ fnaddr = gen_const_mem (Pmode, fnaddr);
+ return ix86_output_call_insn (insn, fnaddr);
+}
+ [(set_attr "type" "call")])
+
(define_insn "*sibcall"
[(call (mem:QI (match_operand:W 0 "sibcall_insn_operand" "UBsBz"))
(match_operand 1))]
@@ -12042,6 +12064,29 @@
"* return ix86_output_call_insn (insn, operands[1]);"
[(set_attr "type" "callv")])
+;; Since sibcall never returns, we can only use call-clobbered register
+;; as GOT base.
+(define_insn "*sibcall_value_GOT_32"
+ [(set (match_operand 0)
+ (call (mem:QI
+ (mem:SI (plus:SI
+ (match_operand:SI 1 "register_operand" "U")
+ (const:SI
+ (unspec:SI [(match_operand:SI 2 "symbol_operand")]
+ UNSPEC_GOT)))))
+ (match_operand 3)))
+ (clobber (match_dup 1))]
+ "!TARGET_MACHO && !TARGET_64BIT && SIBLING_CALL_P (insn)"
+{
+ rtx fnaddr = gen_rtx_UNSPEC (Pmode, gen_rtvec (1, operands[2]),
+ UNSPEC_GOT);
+ fnaddr = gen_rtx_CONST (Pmode, fnaddr);
+ fnaddr = gen_rtx_PLUS (Pmode, operands[1], fnaddr);
+ fnaddr = gen_const_mem (Pmode, fnaddr);
+ return ix86_output_call_insn (insn, fnaddr);
+}
+ [(set_attr "type" "callv")])
+
(define_insn "*sibcall_value"
[(set (match_operand 0)
(call (mem:QI (match_operand:W 1 "sibcall_insn_operand" "UBsBz"))
diff --git a/gcc/testsuite/gcc.target/i386/pr68937-1.c
b/gcc/testsuite/gcc.target/i386/pr68937-1.c
new file mode 100644
index 0000000..166c309
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr68937-1.c
@@ -0,0 +1,13 @@
+/* { dg-do compile { target { *-*-linux* && ia32 } } } */
+/* { dg-options "-O2 -fpic -fno-plt -mregparm=3" } */
+
+extern void bar (int);
+
+void
+foo (int b)
+{
+ bar (b);
+ bar (b);
+}
+
+/* { dg-final { scan-assembler "jmp\[ \t\]*.bar@GOT\\(%e(a|c|d)x\\)" { target
ia32 } } } */
diff --git a/gcc/testsuite/gcc.target/i386/pr68937-2.c
b/gcc/testsuite/gcc.target/i386/pr68937-2.c
new file mode 100644
index 0000000..9aa4f4d
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr68937-2.c
@@ -0,0 +1,13 @@
+/* { dg-do compile { target { *-*-linux* && ia32 } } } */
+/* { dg-options "-O2 -fpic -fno-plt -mregparm=3" } */
+
+extern void bar (int, int);
+
+void
+foo (int a, int b)
+{
+ bar (a, b);
+ bar (a, b);
+}
+
+/* { dg-final { scan-assembler "jmp\[ \t\]*.bar@GOT\\(%e(a|c|d)x\\)" { target
ia32 } } } */
diff --git a/gcc/testsuite/gcc.target/i386/pr68937-3.c
b/gcc/testsuite/gcc.target/i386/pr68937-3.c
new file mode 100644
index 0000000..6d8e40f
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr68937-3.c
@@ -0,0 +1,13 @@
+/* { dg-do compile { target { *-*-linux* && ia32 } } } */
+/* { dg-options "-O2 -fpic -fno-plt -mregparm=3" } */
+
+extern void bar (int, int, int);
+
+void
+foo (int a, int b, int c)
+{
+ bar (a, b, c);
+ bar (a, b, c);
+}
+
+/* { dg-final { scan-assembler-not "jmp\[ \t\]*.bar@GOT" } } */
diff --git a/gcc/testsuite/gcc.target/i386/pr68937-4.c
b/gcc/testsuite/gcc.target/i386/pr68937-4.c
new file mode 100644
index 0000000..fc5f2a6
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr68937-4.c
@@ -0,0 +1,13 @@
+/* { dg-do compile { target { *-*-linux* && ia32 } } } */
+/* { dg-options "-O2 -fpic -fno-plt -mregparm=3" } */
+
+extern int bar (int, int);
+
+int
+foo (int a, int b)
+{
+ (void) bar (a, b);
+ return bar (a, b);
+}
+
+/* { dg-final { scan-assembler "jmp\[ \t\]*.bar@GOT\\(%e(a|c|d)x\\)" { target
ia32 } } } */
--
2.5.0
