or1k: Fix issue with set_got clobbering r9
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Message ID 20190822114404.1318-1-shorne@gmail.com
State New
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  • or1k: Fix issue with set_got clobbering r9
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Commit Message

Stafford Horne Aug. 22, 2019, 11:44 a.m. UTC
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(-)

Comments

Stafford Horne Aug. 30, 2019, 9:31 a.m. UTC | #1
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
>
Richard Henderson Aug. 30, 2019, 3:21 p.m. UTC | #2
LGTM.

On 8/30/19 2:31 AM, Stafford Horne wrote:
> 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
>>
Stafford Horne Aug. 30, 2019, 9:37 p.m. UTC | #3
On Fri, Aug 30, 2019 at 08:21:56AM -0700, Richard Henderson wrote:
> LGTM.

Thank you.
 
> On 8/30/19 2:31 AM, Stafford Horne wrote:
> > 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
> >>
>

Patch
diff mbox series

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 - 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))]
   ""