Interrupt

10 files changed, 283 insertions, 15 deletions

diff --git a/gcc/config/i386/i386-protos.h b/gcc/config/i386/i386-protos.h
index 6a17ef40a2e..cac267d9a9b 100644
--- a/gcc/config/i386/i386-protos.h
+++ b/gcc/config/i386/i386-protos.h
@@ -26,6 +26,8 @@ extern bool ix86_handle_option (struct gcc_options *opts,
 /* Functions in i386.c */
 extern bool ix86_target_stack_probe (void);
 extern bool ix86_can_use_return_insn_p (void);
+extern bool ix86_is_interrupt_p (void);
+extern bool ix86_is_exception_p (void);
 extern void ix86_setup_frame_addresses (void);
 
 extern HOST_WIDE_INT ix86_initial_elimination_offset (int, int);
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 7a97f3725d2..5c486f8b403 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -4503,16 +4503,6 @@ ix86_conditional_register_usage (void)
 {
   int i, c_mask;
 
-  /* For 32-bit targets, squash the REX registers.  */
-  if (! TARGET_64BIT)
-    {
-      for (i = FIRST_REX_INT_REG; i <= LAST_REX_INT_REG; i++)
-	fixed_regs[i] = call_used_regs[i] = 1, reg_names[i] = "";
-      for (i = FIRST_REX_SSE_REG; i <= LAST_REX_SSE_REG; i++)
-	fixed_regs[i] = call_used_regs[i] = 1, reg_names[i] = "";
-      for (i = FIRST_EXT_REX_SSE_REG; i <= LAST_EXT_REX_SSE_REG; i++)
-	fixed_regs[i] = call_used_regs[i] = 1, reg_names[i] = "";
-    }
 
   /*  See the definition of CALL_USED_REGISTERS in i386.h.  */
   c_mask = (TARGET_64BIT_MS_ABI ? (1 << 3)
@@ -4535,6 +4525,39 @@ ix86_conditional_register_usage (void)
 	SET_HARD_REG_BIT (reg_class_contents[(int)CLOBBERED_REGS], i);
     }
 
+  if (current_function_decl && ix86_is_interrupt_p ())
+    {
+      for (i = AX_REG; i <= DI_REG; i++)
+        {
+          call_used_regs[i] = 0;
+          fixed_regs[i] = 0;
+        }
+      for (i = XMM0_REG; i <= XMM7_REG; i++)
+        {
+          call_used_regs[i] = 0;
+          fixed_regs[i] =  0;
+        }
+      for (i = R8_REG; i <FIRST_PSEUDO_REGISTER; i++)
+        {
+          call_used_regs[i] = 0;
+          fixed_regs[i] =  0;
+        }
+    }
+
+
+  /* For 32-bit targets, squash the REX registers.  */
+  if (! TARGET_64BIT)
+    {
+      for (i = FIRST_REX_INT_REG; i <= LAST_REX_INT_REG; i++)
+	fixed_regs[i] = call_used_regs[i] = 1, reg_names[i] = "";
+      for (i = FIRST_REX_SSE_REG; i <= LAST_REX_SSE_REG; i++)
+	fixed_regs[i] = call_used_regs[i] = 1, reg_names[i] = "";
+      for (i = FIRST_EXT_REX_SSE_REG; i <= LAST_EXT_REX_SSE_REG; i++)
+	fixed_regs[i] = call_used_regs[i] = 1, reg_names[i] = "";
+    }
+
+
+
   /* If MMX is disabled, squash the registers.  */
   if (! TARGET_MMX)
     for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
@@ -5562,6 +5585,10 @@ ix86_function_ok_for_sibcall (tree decl, tree exp)
   tree type, decl_or_type;
   rtx a, b;
 
+  if (ix86_is_interrupt_p ())
+    return false;
+
+
   /* If we are generating position-independent code, we cannot sibcall
      optimize direct calls to global functions, as the PLT requires
      %ebx be live. (Darwin does not have a PLT.)  */
@@ -6440,8 +6467,10 @@ ix86_call_abi_override (const_tree fndecl)
 static void
 ix86_maybe_switch_abi (void)
 {
-  if (TARGET_64BIT &&
-      call_used_regs[SI_REG] == (cfun->machine->call_abi == MS_ABI))
+  if (call_used_regs[AX_REG] == ix86_is_interrupt_p ())
+      reinit_regs ();
+  else if ((TARGET_64BIT &&
+      call_used_regs[SI_REG] == (cfun->machine->call_abi == MS_ABI)))
     reinit_regs ();
 }
 
@@ -10135,7 +10164,7 @@ ix86_nsaved_sseregs (void)
   int nregs = 0;
   int regno;
 
-  if (!TARGET_64BIT_MS_ABI)
+  if (!TARGET_64BIT_MS_ABI && !ix86_is_interrupt_p ())
     return 0;
   for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
     if (SSE_REGNO_P (regno) && ix86_save_reg (regno, true))
@@ -11466,6 +11495,14 @@ ix86_expand_prologue (void)
   /* DRAP should not coexist with stack_realign_fp */
   gcc_assert (!(crtl->drap_reg && stack_realign_fp));
 
+ if (ix86_is_interrupt_p () && ix86_using_red_zone ())
+    {
+      emit_insn (gen_adddi3 (
+                   gen_rtx_REG (DImode, SP_REG),
+                   gen_rtx_REG (DImode, SP_REG),
+                   GEN_INT (-128)));
+    }
+
   memset (&m->fs, 0, sizeof (m->fs));
 
   /* Initialize CFA state for before the prologue.  */
@@ -12437,7 +12474,29 @@ ix86_expand_epilogue (int style)
       return;
     }
 
-  if (crtl->args.pops_args && crtl->args.size)
+  if (ix86_is_interrupt_p ())
+    {
+      if (ix86_using_red_zone ())
+          emit_insn (gen_adddi3 (
+                   gen_rtx_REG (DImode, SP_REG),
+                   gen_rtx_REG (DImode, SP_REG),
+                   GEN_INT (128)));
+      if (ix86_is_exception_p ())
+        {
+          if (!TARGET_64BIT)
+            emit_insn (gen_addsi3 (
+                   gen_rtx_REG (SImode, SP_REG),
+                   gen_rtx_REG (SImode, SP_REG),
+                   GEN_INT (POINTER_SIZE_UNITS)));
+          else
+            emit_insn (gen_adddi3 (
+                   gen_rtx_REG (DImode, SP_REG),
+                   gen_rtx_REG (DImode, SP_REG),
+                   GEN_INT (POINTER_SIZE_UNITS)));
+        }
+      emit_jump_insn (gen_simple_return_interrupt ());
+    }
+  else if (crtl->args.pops_args && crtl->args.size)
     {
       rtx popc = GEN_INT (crtl->args.pops_args);
 
@@ -25752,12 +25811,23 @@ ix86_expand_call (rtx retval, rtx fnaddr, rtx callarg1,
 	}
     }
 
+  if (ix86_is_interrupt_p ())
+    {
+      unsigned regno;
+      for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
+      {
+      if (!call_used_regs[regno] && !fixed_regs[regno] && !STACK_REGNO_P (regno) && !MMX_REGNO_P (regno))
+        {
+          clobber_reg(&use, gen_rtx_REG (GET_MODE(regno_reg_rtx[regno]), regno));
+        }
+      }
+    }
+
   if (vec_len > 1)
     call = gen_rtx_PARALLEL (VOIDmode, gen_rtvec_v (vec_len, vec));
   call = emit_call_insn (call);
   if (use)
     CALL_INSN_FUNCTION_USAGE (call) = use;
-
   return call;
 }
 
@@ -42204,6 +42274,23 @@ ix86_hard_regno_mode_ok (int regno, machine_mode mode)
   return false;
 }
 
+bool
+ix86_is_interrupt_p ()
+{
+  return lookup_attribute ("interrupt",
+           DECL_ATTRIBUTES (current_function_decl)) ||
+         lookup_attribute ("exception",
+           DECL_ATTRIBUTES (current_function_decl));
+}
+
+bool
+ix86_is_exception_p ()
+{
+  return lookup_attribute ("exception",
+           DECL_ATTRIBUTES (current_function_decl));
+}
+
+
 /* A subroutine of ix86_modes_tieable_p.  Return true if MODE is a
    tieable integer mode.  */
 
@@ -43126,6 +43213,51 @@ ix86_handle_fndecl_attribute (tree *node, tree name, tree, int,
   return NULL_TREE;
 }
 
+
+static tree
+ix86_handle_interrupt_attribute (tree *node, tree name, tree, int,
+                                 bool *no_add_attrs)
+{
+  if (TREE_CODE (*node) != FUNCTION_DECL)
+    {
+      warning (OPT_Wattributes, "%qE attribute only applies to functions",
+               name);
+      *no_add_attrs = true;
+    }
+
+  /* DECL_RESULT and DECL_ARGUMENTS do not exist there yet,
+     but the function type contains args and return type data.  */
+  tree func_type = TREE_TYPE (*node);
+  tree first_arg_type = TYPE_ARG_TYPES (func_type);
+  tree return_type = TREE_TYPE (func_type);
+  if (first_arg_type && ! VOID_TYPE_P ( TREE_VALUE (first_arg_type)))
+    error ("Interrupt service routine can't have arguments");
+  if (! VOID_TYPE_P (return_type))
+    error ("Interrupt service routine can't have non-void return value");
+
+  return NULL_TREE;
+}
+
+static tree
+ix86_handle_exception_attribute (tree *node, tree name, tree, int,
+                                 bool *no_add_attrs)
+{
+  if (TREE_CODE (*node) != FUNCTION_DECL)
+    {
+      warning (OPT_Wattributes, "%qE attribute only applies to functions",
+               name);
+      *no_add_attrs = true;
+    }
+
+  tree func_type = TREE_TYPE (*node);
+  tree return_type = TREE_TYPE (func_type);
+  if (! VOID_TYPE_P (return_type))
+    error ("Interrupt service routine can't have non-void return value");
+
+  return NULL_TREE;
+}
+
+
 static bool
 ix86_ms_bitfield_layout_p (const_tree record_type)
 {
@@ -47127,6 +47259,11 @@ static const struct attribute_spec ix86_attribute_table[] =
     false },
   { "callee_pop_aggregate_return", 1, 1, false, true, true,
     ix86_handle_callee_pop_aggregate_return, true },
+{ "interrupt", 0, 0, true, false, false, ix86_handle_interrupt_attribute,
+    false },
+  { "exception", 0, 0, true, false, false, ix86_handle_exception_attribute,
+    false },
+
   /* End element.  */
   { NULL,        0, 0, false, false, false, NULL, false }
 };
diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index 7017913afe2..b7568ba0c22 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -193,6 +193,9 @@
   UNSPEC_BNDCU
   UNSPEC_BNDCN
   UNSPEC_MPX_FENCE
+
+  ;; IRET support
+  UNSPEC_INTERRUPT_RETURN
 ])
 
 (define_c_enum "unspecv" [
@@ -12094,6 +12097,12 @@
    (set_attr "modrm" "0")
    (set_attr "maybe_prefix_bnd" "1")])
 
+(define_insn "simple_return_interrupt"
+  [(simple_return)
+   (unspec [(const_int 0)] UNSPEC_INTERRUPT_RETURN)]
+  ""
+  "iret")
+
 ;; Used by x86_machine_dependent_reorg to avoid penalty on single byte RET
 ;; instruction Athlon and K8 have.
 
diff --git a/gcc/testsuite/gcc.target/i386/interrupt-args-err.c b/gcc/testsuite/gcc.target/i386/interrupt-args-err.c
new file mode 100644
index 00000000000..1ea093e25a7
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/interrupt-args-err.c
@@ -0,0 +1,9 @@
+/* { dg-do compile } */
+
+extern void foo (int,int) __attribute__ ((interrupt)); /* { dg-error "Interrupt service routine can't have arguments" } */
+extern void bar (int, int);
+
+void foo (int x, int y)
+{
+  bar (x, y);
+}
diff --git a/gcc/testsuite/gcc.target/i386/interrupt-iamcu.c b/gcc/testsuite/gcc.target/i386/interrupt-iamcu.c
new file mode 100644
index 00000000000..9c9d266cec2
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/interrupt-iamcu.c
@@ -0,0 +1,33 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -march=iamcu" } */
+
+extern void foo (void) __attribute__ ((interrupt));
+extern int bar (int);
+
+void foo ()
+{
+  int a,b,c,d,e,f,i;
+  a = bar(5);
+  b = bar(a);
+  c = bar(b);
+  d = bar(c);
+  e = bar(d);
+  f = bar(e);
+  for (i = 1; i < 10; i++)
+  {
+    a += bar (a + i) + bar(b + i) + bar(c + i) + bar(d + i) + bar(e + i) + bar(f+i);
+  }
+}
+/* { dg-final { scan-assembler "push.\t%.ax" } }*/
+/* { dg-final { scan-assembler "pop.\t%.ax" } }*/
+/* { dg-final { scan-assembler "push.\t%.dx" } }*/
+/* { dg-final { scan-assembler "pop.\t%.dx" } }*/
+/* { dg-final { scan-assembler "push.\t%.cx" } }*/
+/* { dg-final { scan-assembler "pop.\t%.cx" } }*/
+/* { dg-final { scan-assembler "push.\t%.bx" } }*/
+/* { dg-final { scan-assembler "pop.\t%.bx" } }*/
+/* { dg-final { scan-assembler "push.\t%.si" } }*/
+/* { dg-final { scan-assembler "pop.\t%.si" } }*/
+/* { dg-final { scan-assembler "push.\t%.di" } }*/
+/* { dg-final { scan-assembler "pop.\t%.di" } }*/
+/* { dg-final { scan-assembler "iret" } }*/
diff --git a/gcc/testsuite/gcc.target/i386/interrupt-redzone.c b/gcc/testsuite/gcc.target/i386/interrupt-redzone.c
new file mode 100644
index 00000000000..d59eb663966
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/interrupt-redzone.c
@@ -0,0 +1,10 @@
+/* { dg-do compile { target { ! { ia32 } } } } */
+/* { dg-options "-mabi=sysv" } */
+extern int a;
+void __attribute__((interrupt)) bar ()
+  {
+    a = 4;
+  }
+
+/* { dg-final { scan-assembler "addq\t\\\$-?128, %rsp" } } */
+/* { dg-final { scan-assembler "subq\t\\\$-?128, %rsp" } } */
diff --git a/gcc/testsuite/gcc.target/i386/interrupt-retval-err.c b/gcc/testsuite/gcc.target/i386/interrupt-retval-err.c
new file mode 100644
index 00000000000..7e8990c8c4d
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/interrupt-retval-err.c
@@ -0,0 +1,11 @@
+/* { dg-do compile } */
+
+extern int foo (void) __attribute__ ((interrupt)); /* { dg-error "Interrupt service routine can't have non-void return value" } */
+extern int bar (int, int);
+
+int foo (void)
+{
+  int x, y;
+  x = y = 1;
+  return bar (x, y);
+}
diff --git a/gcc/testsuite/gcc.target/i386/interrupt-sibcall.c b/gcc/testsuite/gcc.target/i386/interrupt-sibcall.c
new file mode 100644
index 00000000000..6d418bef59a
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/interrupt-sibcall.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-O3" } */
+
+extern void foo (void) __attribute__ ((interrupt));
+extern void bar (void);
+
+void foo ()
+{
+  bar ();
+}
+/* { dg-final { scan-assembler-not "jmp" } }*/
+/* { dg-final { scan-assembler "iret" } }*/
diff --git a/gcc/testsuite/gcc.target/i386/interrupt-switch-abi.c b/gcc/testsuite/gcc.target/i386/interrupt-switch-abi.c
new file mode 100644
index 00000000000..33de0bc4186
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/interrupt-switch-abi.c
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+
+extern void bar(int);
+
+void f1(){  bar(1); }
+__attribute__((interrupt)) 
+void f2(){  bar(2); }
+void f3(){  bar(3); }
+__attribute__((exception)) 
+void f4(){  bar(4); }
+void f5(){  bar(5); }
+
+/* { dg-final { scan-assembler-times "iret" 2 } } */
diff --git a/gcc/testsuite/gcc.target/i386/interrupt.c b/gcc/testsuite/gcc.target/i386/interrupt.c
new file mode 100644
index 00000000000..9153a521640
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/interrupt.c
@@ -0,0 +1,32 @@
+/* { dg-do compile } */
+
+extern void foo (void) __attribute__ ((interrupt));
+extern int bar (int);
+
+void foo ()
+{
+  int a,b,c,d,e,f,i;
+  a = bar(5);
+  b = bar(a);
+  c = bar(b);
+  d = bar(c);
+  e = bar(d);
+  f = bar(e);
+  for (i = 1; i < 10; i++)
+  {
+    a += bar (a + i) + bar(b + i) + bar(c + i) + bar(d + i) + bar(e + i) + bar(f+i);
+  }
+}
+/* { dg-final { scan-assembler "push.\t%.ax" } }*/
+/* { dg-final { scan-assembler "pop.\t%.ax" } }*/
+/* { dg-final { scan-assembler "push.\t%.dx" } }*/
+/* { dg-final { scan-assembler "pop.\t%.dx" } }*/
+/* { dg-final { scan-assembler "push.\t%.cx" } }*/
+/* { dg-final { scan-assembler "pop.\t%.cx" } }*/
+/* { dg-final { scan-assembler "push.\t%.bx" } }*/
+/* { dg-final { scan-assembler "pop.\t%.bx" } }*/
+/* { dg-final { scan-assembler "push.\t%.si" } }*/
+/* { dg-final { scan-assembler "pop.\t%.si" } }*/
+/* { dg-final { scan-assembler "push.\t%.di" } }*/
+/* { dg-final { scan-assembler "pop.\t%.di" } }*/
+/* { dg-final { scan-assembler "iret" } }*/