Hi
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 during epilogue/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.
Testing done: Bootstrapped and regtested on arm-none-linux-gnueabihf
and added the reported test to the testsuite.
Is this ok for trunk?
Sudi
ChangeLog entries:
*** gcc/ChangeLog ***
2018-03-21 Sudakshina Das <sudi....@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 ***
2018-03-21 Sudakshina Das <sudi....@arm.com>
PR target/84826
* gcc.target/arm/pr84826.c: New test
diff --git a/gcc/config/arm/arm.h b/gcc/config/arm/arm.h
index bbf3937..2809112 100644
--- a/gcc/config/arm/arm.h
+++ b/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
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index cb6ab81..bc31810 100644
--- a/gcc/config/arm/arm.c
+++ b/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 the -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;
}
diff --git a/gcc/testsuite/gcc.target/arm/pr84826.c b/gcc/testsuite/gcc.target/arm/pr84826.c
new file mode 100644
index 0000000..c61c548
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/pr84826.c
@@ -0,0 +1,15 @@
+/* { 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);
+}
