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PATCH: PR target/47715: [x32] Use SImode for thread pointer

Message ID CAMe9rOoeUD4xZysQ7dqApLm7iOWuXnhwc917Nx8ySrZh6Hg2zw@mail.gmail.com
State New
Headers show

Commit Message

H.J. Lu July 28, 2011, 2:57 p.m. UTC 
On Thu, Jul 28, 2011 at 6:40 AM, Uros Bizjak <ubizjak@gmail.com> wrote:
> On Thu, Jul 28, 2011 at 3:24 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
>
>>>>> In x32, thread pointer is 32bit and choice of segment register for the
>>>>> thread base ptr load should be based on TARGET_64BIT.  This patch
>>>>> implements it.  OK for trunk?
>>>>
>>>> -ENOTESTCASE.
>>>>
>>>
>>> There is no standalone testcase.  The symptom is in glibc build, I
>>> got
>>>
>>> CPP='/export/build/gnu/gcc-x32/release/usr/gcc-4.7.0-x32/bin/gcc -mx32
>>>  -E -x c-header'
>>> /export/build/gnu/glibc-x32/build-x86_64-linux/elf/ld-linux-x32.so.2
>>> --library-path /export/build/gnu/glibc-x32/build-x86_64-linux:/export/build/gnu/glibc-x32/build-x86_64-linux/math:/export/build/gnu/glibc-x32/build-x86_64-linux/elf:/export/build/gnu/glibc-x32/build-x86_64-linux/dlfcn:/export/build/gnu/glibc-x32/build-x86_64-linux/nss:/export/build/gnu/glibc-x32/build-x86_64-linux/nis:/export/build/gnu/glibc-x32/build-x86_64-linux/rt:/export/build/gnu/glibc-x32/build-x86_64-linux/resolv:/export/build/gnu/glibc-x32/build-x86_64-linux/crypt:/export/build/gnu/glibc-x32/build-x86_64-linux/nptl
>>> /export/build/gnu/glibc-x32/build-x86_64-linux/sunrpc/rpcgen -Y
>>> ../scripts -h rpcsvc/yppasswd.x -o
>>> /export/build/gnu/glibc-x32/build-x86_64-linux/sunrpc/rpcsvc/yppasswd.T
>>> make[5]: *** [/export/build/gnu/glibc-x32/build-x86_64-linux/sunrpc/xbootparam_prot.stmp]
>>> Segmentation fault
>>> make[5]: *** Waiting for unfinished jobs....
>>> make[5]: *** [/export/build/gnu/glibc-x32/build-x86_64-linux/sunrpc/xrstat.stmp]
>>> Segmentation fault
>>> make[5]: *** [/export/build/gnu/glibc-x32/build-x86_64-linux/sunrpc/xyppasswd.stmp]
>>> Segmentation fault
>>>
>>> since thread pointer is 32bit in x32.
>>>
>>
>> If we load thread pointer (fs segment register) in x32 with 64bit
>> load, the upper 32bits are garbage.
>> We must load 32bit
>
> So, instead of huge complications with new mode iterator, just
> introduce two new patterns that will shadow existing ones for
> TARGET_X32.
>
> Like in attached (untested) patch.
>

We can't just shadow them. They have to be disabled for x32.
I am testing this.
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Patch

diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index aaaf53a..9191b98 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -12452,10 +12452,21 @@ 
 (define_mode_attr tp_seg [(SI "gs") (DI "fs")])

 ;; Load and add the thread base pointer from %<tp_seg>:0.
+(define_insn "*load_tp_x32"
+  [(set (match_operand:DI 0 "register_operand" "=r")
+	(unspec:DI [(const_int 0)] UNSPEC_TP))]
+  "TARGET_X32"
+  "mov{l}\t{%%fs:0, %k0|%k0, DWORD PTR fs:0}"
+  [(set_attr "type" "imov")
+   (set_attr "modrm" "0")
+   (set_attr "length" "7")
+   (set_attr "memory" "load")
+   (set_attr "imm_disp" "false")])
+
 (define_insn "*load_tp_<mode>"
   [(set (match_operand:P 0 "register_operand" "=r")
 	(unspec:P [(const_int 0)] UNSPEC_TP))]
-  ""
+  "!TARGET_X32"
   "mov{<imodesuffix>}\t{%%<tp_seg>:0, %0|%0, <iptrsize> PTR <tp_seg>:0}"
   [(set_attr "type" "imov")
    (set_attr "modrm" "0")
@@ -12463,12 +12474,25 @@ 
    (set_attr "memory" "load")
    (set_attr "imm_disp" "false")])

+(define_insn "*add_tp_x32"
+  [(set (match_operand:DI 0 "register_operand" "=r")
+	(plus:DI (unspec:DI [(const_int 0)] UNSPEC_TP)
+		 (match_operand:DI 1 "register_operand" "0")))
+   (clobber (reg:CC FLAGS_REG))]
+  "TARGET_X32"
+  "add{l}\t{%%fs:0, %k0|%k0, DWORD PTR fs:0}"
+  [(set_attr "type" "alu")
+   (set_attr "modrm" "0")
+   (set_attr "length" "7")
+   (set_attr "memory" "load")
+   (set_attr "imm_disp" "false")])
+
 (define_insn "*add_tp_<mode>"
   [(set (match_operand:P 0 "register_operand" "=r")
 	(plus:P (unspec:P [(const_int 0)] UNSPEC_TP)
 		(match_operand:P 1 "register_operand" "0")))
    (clobber (reg:CC FLAGS_REG))]
-  ""
+  "!TARGET_X32"
   "add{<imodesuffix>}\t{%%<tp_seg>:0, %0|%0, <iptrsize> PTR <tp_seg>:0}"
   [(set_attr "type" "alu")
    (set_attr "modrm" "0")