From f6955089db6c3aa63c276704159ffad1ef15d256 Mon Sep 17 00:00:00 2001 From: Xionghu Luo Date: Sun, 26 Apr 2020 20:37:27 -0500 Subject: [PATCH] rs6000: Don't use HARD_FRAME_POINTER_REGNUM if it's not live in pro_and_epilogue (PR91518) This bug is exposed by FRE refactor of r263875. Comparing the fre dump file shows no obvious change of the segment fault function proves it to be a target issue. frame_pointer_needed is set to true in reload pass setup_can_eliminate, but regs_ever_live[31] is false, pro_and_epilogue uses it without live check causing CPU2006 465.tonto segment fault of loading from invalid addresses due to r31 not saved/restored. Thus, add HARD_FRAME_POINTER_REGNUM live check with frame_pointer_needed_indeed when generating pro_and_epilogue instructions. gcc/ChangeLog 2020-04-27 Xiong Hu Luo PR target/91518 * config/rs6000/rs6000-logue.c (frame_pointer_needed_indeed): New variable. (rs6000_emit_prologue_components): Check with frame_pointer_needed_indeed. (rs6000_emit_epilogue_components): Likewise. (rs6000_emit_prologue): Likewise. (rs6000_emit_epilogue): Set frame_pointer_needed_indeed. --- gcc/ChangeLog | 11 +++++++++++ gcc/config/rs6000/rs6000-logue.c | 23 ++++++++++++++--------- 2 files changed, 25 insertions(+), 9 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 38dd583..36b5720 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,14 @@ +2020-04-27 Xiong Hu Luo + + PR target/91518 + * config/rs6000/rs6000-logue.c (frame_pointer_needed_indeed): + New variable. + (rs6000_emit_prologue_components): + Check with frame_pointer_needed_indeed. + (rs6000_emit_epilogue_components): Likewise. + (rs6000_emit_prologue): Likewise. + (rs6000_emit_epilogue): Set frame_pointer_needed_indeed. + 2020-04-25 David Edelsohn * config/rs6000/rs6000-logue.c (rs6000_stack_info): Don't push a diff --git a/gcc/config/rs6000/rs6000-logue.c b/gcc/config/rs6000/rs6000-logue.c index 7226319..6aad1ff 100644 --- a/gcc/config/rs6000/rs6000-logue.c +++ b/gcc/config/rs6000/rs6000-logue.c @@ -58,6 +58,8 @@ static bool rs6000_save_toc_in_prologue_p (void); static rs6000_stack_t stack_info; +/* Set if HARD_FRAM_POINTER_REGNUM is really needed. */ +static bool frame_pointer_needed_indeed = false; /* Label number of label created for -mrelocatable, to call to so we can get the address of the GOT section */ @@ -2735,9 +2737,9 @@ void rs6000_emit_prologue_components (sbitmap components) { rs6000_stack_t *info = rs6000_stack_info (); - rtx ptr_reg = gen_rtx_REG (Pmode, frame_pointer_needed - ? HARD_FRAME_POINTER_REGNUM - : STACK_POINTER_REGNUM); + rtx ptr_reg = gen_rtx_REG (Pmode, frame_pointer_needed_indeed + ? HARD_FRAME_POINTER_REGNUM + : STACK_POINTER_REGNUM); machine_mode reg_mode = Pmode; int reg_size = TARGET_32BIT ? 4 : 8; @@ -2815,9 +2817,9 @@ void rs6000_emit_epilogue_components (sbitmap components) { rs6000_stack_t *info = rs6000_stack_info (); - rtx ptr_reg = gen_rtx_REG (Pmode, frame_pointer_needed - ? HARD_FRAME_POINTER_REGNUM - : STACK_POINTER_REGNUM); + rtx ptr_reg = gen_rtx_REG (Pmode, frame_pointer_needed_indeed + ? HARD_FRAME_POINTER_REGNUM + : STACK_POINTER_REGNUM); machine_mode reg_mode = Pmode; int reg_size = TARGET_32BIT ? 4 : 8; @@ -2996,7 +2998,10 @@ rs6000_emit_prologue (void) && (lookup_attribute ("no_split_stack", DECL_ATTRIBUTES (cfun->decl)) == NULL)); - + + frame_pointer_needed_indeed + = frame_pointer_needed && df_regs_ever_live_p (HARD_FRAME_POINTER_REGNUM); + /* Offset to top of frame for frame_reg and sp respectively. */ HOST_WIDE_INT frame_off = 0; HOST_WIDE_INT sp_off = 0; @@ -3658,7 +3663,7 @@ rs6000_emit_prologue (void) } /* Set frame pointer, if needed. */ - if (frame_pointer_needed) + if (frame_pointer_needed_indeed) { insn = emit_move_insn (gen_rtx_REG (Pmode, HARD_FRAME_POINTER_REGNUM), sp_reg_rtx); @@ -4534,7 +4539,7 @@ rs6000_emit_epilogue (enum epilogue_type epilogue_type) } /* If we have a frame pointer, we can restore the old stack pointer from it. */ - else if (frame_pointer_needed) + else if (frame_pointer_needed_indeed) { frame_reg_rtx = sp_reg_rtx; if (DEFAULT_ABI == ABI_V4) -- 2.7.4