[PATCH] or1k: Fix issue with set_got clobbering r9
Stafford Horne
shorne@gmail.com
Fri Aug 30 10:09:00 GMT 2019
Hello, any comments on this?
If nothing I will commit in a few days.
On Thu, Aug 22, 2019 at 08:44:04PM +0900, Stafford Horne wrote:
> When compiling glibc we found that the GOT register was being allocated
> r9 when the instruction was still set_got_tmp. That caused set_got to
> clobber r9. We cannot simply say set_got_tmp clobbers r9 as this is the
> reason for having the temporary set_got_tmp.
>
> Fix by using a register class constraint that does not allow r9 during
> register allocation.
>
> gcc/ChangeLog:
>
> * config/or1k/constraints.md (t): New constraint.
> * config/or1k/or1k.h (GOT_REGS): New register class.
> * config/or1k/or1k.md (set_got_tmp, set_got): Use t contraint.
> ---
> gcc/config/or1k/constraints.md | 4 ++++
> gcc/config/or1k/or1k.h | 3 +++
> gcc/config/or1k/or1k.md | 4 ++--
> 3 files changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/gcc/config/or1k/constraints.md b/gcc/config/or1k/constraints.md
> index 8cac7eb5329..ba330c6b8c2 100644
> --- a/gcc/config/or1k/constraints.md
> +++ b/gcc/config/or1k/constraints.md
> @@ -25,6 +25,7 @@
> ; We use:
> ; c - sibcall registers
> ; d - double pair base registers (excludes r0, r30 and r31 which overflow)
> +; t - got address registers (excludes r9 is clobbered by set_got)
I will changee this to (... r9 which is clobbered ...)
> ; I - constant signed 16-bit
> ; K - constant unsigned 16-bit
> ; M - constant signed 16-bit shifted left 16-bits (l.movhi)
> @@ -36,6 +37,9 @@
> (define_register_constraint "d" "DOUBLE_REGS"
> "Registers which can be used for double reg pairs.")
>
> +(define_register_constraint "t" "GOT_REGS"
> + "Registers which can be used to store the Global Offset Table (GOT) address.")
> +
> ;; Immediates
> (define_constraint "I"
> "A signed 16-bit immediate in the range -32768 to 32767."
> diff --git a/gcc/config/or1k/or1k.h b/gcc/config/or1k/or1k.h
> index 2b29e62fdd3..4c32607bac1 100644
> --- a/gcc/config/or1k/or1k.h
> +++ b/gcc/config/or1k/or1k.h
> @@ -190,6 +190,7 @@ enum reg_class
> NO_REGS,
> SIBCALL_REGS,
> DOUBLE_REGS,
> + GOT_REGS,
> GENERAL_REGS,
> FLAG_REGS,
> ALL_REGS,
> @@ -202,6 +203,7 @@ enum reg_class
> "NO_REGS", \
> "SIBCALL_REGS", \
> "DOUBLE_REGS", \
> + "GOT_REGS", \
> "GENERAL_REGS", \
> "FLAG_REGS", \
> "ALL_REGS" }
> @@ -215,6 +217,7 @@ enum reg_class
> { { 0x00000000, 0x00000000 }, \
> { SIBCALL_REGS_MASK, 0 }, \
> { 0x7f7ffffe, 0x00000000 }, \
> + { 0xfffffdff, 0x00000000 }, \
> { 0xffffffff, 0x00000003 }, \
> { 0x00000000, 0x00000004 }, \
> { 0xffffffff, 0x00000007 } \
> diff --git a/gcc/config/or1k/or1k.md b/gcc/config/or1k/or1k.md
> index cee11d078cc..36bcee336ab 100644
> --- a/gcc/config/or1k/or1k.md
> +++ b/gcc/config/or1k/or1k.md
> @@ -706,7 +706,7 @@
> ;; set_got pattern below. This works because the set_got_tmp insn is the
> ;; first insn in the stream and that it isn't moved during RA.
> (define_insn "set_got_tmp"
> - [(set (match_operand:SI 0 "register_operand" "=r")
> + [(set (match_operand:SI 0 "register_operand" "=t")
> (unspec_volatile:SI [(const_int 0)] UNSPECV_SET_GOT))]
> ""
> {
> @@ -715,7 +715,7 @@
>
> ;; The insn to initialize the GOT.
> (define_insn "set_got"
> - [(set (match_operand:SI 0 "register_operand" "=r")
> + [(set (match_operand:SI 0 "register_operand" "=t")
> (unspec:SI [(const_int 0)] UNSPEC_SET_GOT))
> (clobber (reg:SI LR_REGNUM))]
> ""
> --
> 2.21.0
>
More information about the Gcc-patches
mailing list