From 01037aeb478abb6c6c06c07c7368eead9032b677 Mon Sep 17 00:00:00 2001 From: Eric Botcazou Date: Thu, 6 Jun 2013 18:30:02 +0000 Subject: [PATCH] arm.c (arm_r3_live_at_start_p): New predicate. * config/arm/arm.c (arm_r3_live_at_start_p): New predicate. (arm_compute_static_chain_stack_bytes): Use it. Tidy up. (arm_expand_prologue): Likewise. From-SVN: r199752 --- gcc/ChangeLog | 6 ++++++ gcc/config/arm/arm.c | 44 ++++++++++++++++++++++++++------------------ 2 files changed, 32 insertions(+), 18 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 2d144191e2e..787da6fbd03 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2013-06-06 Eric Botcazou + + * config/arm/arm.c (arm_r3_live_at_start_p): New predicate. + (arm_compute_static_chain_stack_bytes): Use it. Tidy up. + (arm_expand_prologue): Likewise. + 2013-06-06 Teresa Johnson PR c++/53743 diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c index 63eb2b76089..033e8bf0f3c 100644 --- a/gcc/config/arm/arm.c +++ b/gcc/config/arm/arm.c @@ -16178,25 +16178,34 @@ arm_compute_save_reg0_reg12_mask (void) return save_reg_mask; } +/* Return true if r3 is live at the start of the function. */ + +static bool +arm_r3_live_at_start_p (void) +{ + /* Just look at cfg info, which is still close enough to correct at this + point. This gives false positives for broken functions that might use + uninitialized data that happens to be allocated in r3, but who cares? */ + return REGNO_REG_SET_P (df_get_live_out (ENTRY_BLOCK_PTR), 3); +} /* Compute the number of bytes used to store the static chain register on the - stack, above the stack frame. We need to know this accurately to get the - alignment of the rest of the stack frame correct. */ + stack, above the stack frame. We need to know this accurately to get the + alignment of the rest of the stack frame correct. */ -static int arm_compute_static_chain_stack_bytes (void) +static int +arm_compute_static_chain_stack_bytes (void) { - unsigned long func_type = arm_current_func_type (); - int static_chain_stack_bytes = 0; - - if (TARGET_APCS_FRAME && frame_pointer_needed && TARGET_ARM && - IS_NESTED (func_type) && - df_regs_ever_live_p (3) && crtl->args.pretend_args_size == 0) - static_chain_stack_bytes = 4; + /* See the defining assertion in arm_expand_prologue. */ + if (TARGET_APCS_FRAME && frame_pointer_needed && TARGET_ARM + && IS_NESTED (arm_current_func_type ()) + && arm_r3_live_at_start_p () + && crtl->args.pretend_args_size == 0) + return 4; - return static_chain_stack_bytes; + return 0; } - /* Compute a bit mask of which registers need to be saved on the stack for the current function. This is used by arm_get_frame_offsets, which may add extra registers. */ @@ -18151,16 +18160,16 @@ arm_expand_prologue (void) } else if (IS_NESTED (func_type)) { - /* The Static chain register is the same as the IP register + /* The static chain register is the same as the IP register used as a scratch register during stack frame creation. To get around this need to find somewhere to store IP whilst the frame is being created. We try the following places in order: - 1. The last argument register. + 1. The last argument register r3. 2. A slot on the stack above the frame. (This only works if the function is not a varargs function). - 3. Register r3, after pushing the argument registers + 3. Register r3 again, after pushing the argument registers onto the stack. Note - we only need to tell the dwarf2 backend about the SP @@ -18168,7 +18177,7 @@ arm_expand_prologue (void) doesn't need to be unwound, as it doesn't contain a value inherited from the caller. */ - if (df_regs_ever_live_p (3) == false) + if (!arm_r3_live_at_start_p ()) insn = emit_set_insn (gen_rtx_REG (SImode, 3), ip_rtx); else if (args_to_push == 0) { @@ -18309,8 +18318,7 @@ arm_expand_prologue (void) if (IS_NESTED (func_type)) { /* Recover the static chain register. */ - if (!df_regs_ever_live_p (3) - || saved_pretend_args) + if (!arm_r3_live_at_start_p () || saved_pretend_args) insn = gen_rtx_REG (SImode, 3); else /* if (crtl->args.pretend_args_size == 0) */ { -- 2.30.2