[ARM][PR target/84826] Fix ICE in extract_insn, at recog.c:2304 on

arm-linux-gnueabi

The ICE in the bug report was happening because the macro
USE_RETURN_INSN (FALSE) was returning different values at different points
in the compilation. This was internally occurring because the function
arm_compute_static_chain_stack_bytes () which was dependent on
arm_r3_live_at_start_p () was giving a different value after the cond_exec
instructions were created in ce3 causing the liveness of r3 to escape up
to the start block.

The function arm_compute_static_chain_stack_bytes () should really only
compute the value once duringepilogue/prologue stage. This pass introduces
a new member 'static_chain_stack_bytes' to the target definition of the
struct machine_function which gets calculated in expand_prologue and is the
value that is returned by arm_compute_static_chain_stack_bytes () beyond that.

ChangeLog entries:

*** gcc/ChangeLog ***

2018-03-22  Sudakshina Das  <sudi.das@arm.com>

	PR target/84826
	* config/arm/arm.h (machine_function): Add static_chain_stack_bytes.
	* config/arm/arm.c (arm_compute_static_chain_stack_bytes): Avoid
	re-computing once computed.
	(arm_expand_prologue): Compute machine->static_chain_stack_bytes.
	(arm_init_machine_status): Initialize
	machine->static_chain_stack_bytes.

*** gcc/testsuite/ChangeLog ***

2018-03-22  Sudakshina Das  <sudi.das@arm.com>

	PR target/84826
	* gcc.target/arm/pr84826.c: New test.

From-SVN: r258777

gcc/ChangeLog

+2018-03-22  Sudakshina Das  <sudi.das@arm.com>
+
+	PR target/84826
+	* config/arm/arm.h (machine_function): Add static_chain_stack_bytes.
+	* config/arm/arm.c (arm_compute_static_chain_stack_bytes): Avoid
+	re-computing once computed.
+	(arm_expand_prologue): Compute machine->static_chain_stack_bytes.
+	(arm_init_machine_status): Initialize
+	machine->static_chain_stack_bytes.
+
 2018-03-22  Kelvin Nilsen  <kelvin@gcc.gnu.org>
 
 	PR target/84760

gcc/config/arm/arm.c

@@ -19392,6 +19392,11 @@ arm_r3_live_at_start_p (void)
 static int
 arm_compute_static_chain_stack_bytes (void)
 {
+  /* Once the value is updated from the init value of -1, do not
+     re-compute.  */
+  if (cfun->machine->static_chain_stack_bytes != -1)
+    return cfun->machine->static_chain_stack_bytes;
+
   /* See the defining assertion in arm_expand_prologue.  */
   if (IS_NESTED (arm_current_func_type ())
       && ((TARGET_APCS_FRAME && frame_pointer_needed && TARGET_ARM)
@@ -21699,6 +21704,11 @@ arm_expand_prologue (void)
       emit_insn (gen_movsi (stack_pointer_rtx, r1));
     }
 
+  /* Let's compute the static_chain_stack_bytes required and store it.  Right
+     now the value must be -1 as stored by arm_init_machine_status ().  */
+  cfun->machine->static_chain_stack_bytes
+    = arm_compute_static_chain_stack_bytes ();
+
   /* The static chain register is the same as the IP register.  If it is
      clobbered when creating the frame, we need to save and restore it.  */
   clobber_ip = IS_NESTED (func_type)
@@ -24875,6 +24885,7 @@ arm_init_machine_status (void)
 #if ARM_FT_UNKNOWN != 0
   machine->func_type = ARM_FT_UNKNOWN;
 #endif
+  machine->static_chain_stack_bytes = -1;
   return machine;
 }
 

gcc/config/arm/arm.h

@@ -1384,6 +1384,9 @@ typedef struct GTY(()) machine_function
   machine_mode thumb1_cc_mode;
   /* Set to 1 after arm_reorg has started.  */
   int after_arm_reorg;
+  /* The number of bytes used to store the static chain register on the
+     stack, above the stack frame.  */
+  int static_chain_stack_bytes;
 }
 machine_function;
 #endif

gcc/testsuite/ChangeLog

+2018-03-22  Sudakshina Das  <sudi.das@arm.com>
+
+	PR target/84826
+	* gcc.target/arm/pr84826.c: New test.
+
 2018-03-22  Christophe Lyon  <christophe.lyon@linaro.org>
 
 	* gcc.target/arm/addr-modes-float.c: Move dg-do before

gcc/testsuite/gcc.target/arm/pr84826.c

+/* { dg-do compile } */
+/* { dg-options "-Ofast -fstack-clash-protection" } */
+
+void d (void *);
+
+void a ()
+{
+  int b;
+  void bar (int c)
+  {
+    if (__builtin_expect (c, 0))
+      ++b;
+  }
+  d (bar);
+}