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* [PATCH] RISC-V: Implment __builtin_thread_pointer
@ 2020-07-07  9:52 Kito Cheng
  2020-07-08 19:59 ` Jim Wilson
  0 siblings, 1 reply; 6+ messages in thread
From: Kito Cheng @ 2020-07-07  9:52 UTC (permalink / raw)
  To: gcc-patches, kito.cheng, jimw; +Cc: Kito Cheng

RISC-V has a dedicate register for thread pointer which is specified in psABI
doc, so we could support __builtin_thread_pointer in straightforward way.

Note: clang/llvm was supported __builtin_thread_pointer for RISC-V port
recently.
- https://reviews.llvm.org/rGaabc24acf0d5f8677bd22fe9c108581e07c3e180

gcc/ChangeLog:

	* gcc/config/riscv/riscv.md (): New.
	(TP_REGNUM): Ditto.
	* doc/extend.texi (Target Builtins): Add RISC-V built-in section.
	Document __builtin_thread_pointer.

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/read-thread-pointer.c: New.
---
 gcc/config/riscv/riscv.md                            |  8 ++++++++
 gcc/doc/extend.texi                                  | 11 +++++++++++
 gcc/testsuite/gcc.target/riscv/read-thread-pointer.c |  7 +++++++
 3 files changed, 26 insertions(+)
 create mode 100644 gcc/testsuite/gcc.target/riscv/read-thread-pointer.c

diff --git a/gcc/config/riscv/riscv.md b/gcc/config/riscv/riscv.md
index 36012ad1f778..95a02ecaa34b 100644
--- a/gcc/config/riscv/riscv.md
+++ b/gcc/config/riscv/riscv.md
@@ -70,6 +70,7 @@
 (define_constants
   [(RETURN_ADDR_REGNUM		1)
    (GP_REGNUM 			3)
+   (TP_REGNUM			4)
    (T0_REGNUM			5)
    (T1_REGNUM			6)
    (S0_REGNUM			8)
@@ -2515,6 +2516,13 @@
   DONE;
 })
 
+;; Named pattern for expanding thread pointer reference.
+(define_expand "get_thread_pointer<mode>"
+  [(set (match_operand:P 0 "register_operand" "=r")
+	(reg:P TP_REGNUM))]
+  ""
+{})
+
 (include "sync.md")
 (include "peephole.md")
 (include "pic.md")
diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index ecd3661d2571..556c98f46911 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -13859,6 +13859,7 @@ instructions, but allow the compiler to schedule those calls.
 * PowerPC Hardware Transactional Memory Built-in Functions::
 * PowerPC Atomic Memory Operation Functions::
 * PowerPC Matrix-Multiply Assist Built-in Functions::
+* RISC-V Built-in Functions::
 * RX Built-in Functions::
 * S/390 System z Built-in Functions::
 * SH Built-in Functions::
@@ -21461,6 +21462,16 @@ vec_t __builtin_vsx_xvcvspbf16 (vec_t);
 vec_t __builtin_vsx_xvcvbf16sp (vec_t);
 @end smallexample
 
+@node RISC-V Built-in Functions
+@subsection RISC-V Built-in Functions
+
+These built-in functions are available for the RISC-V family of
+processors.
+
+@deftypefn {Built-in Function} {void *} __builtin_thread_pointer (void)
+Returns the value that is currently set in the @samp{tp} register.
+@end deftypefn
+
 @node RX Built-in Functions
 @subsection RX Built-in Functions
 GCC supports some of the RX instructions which cannot be expressed in
diff --git a/gcc/testsuite/gcc.target/riscv/read-thread-pointer.c b/gcc/testsuite/gcc.target/riscv/read-thread-pointer.c
new file mode 100644
index 000000000000..760f8eafb406
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/read-thread-pointer.c
@@ -0,0 +1,7 @@
+/* { dg-do compile } */
+
+void *get_tp()
+{
+    return __builtin_thread_pointer ();
+}
+/* { dg-final { scan-assembler "mv\[ \t\]*[at][0-9]+,tp" } } */
-- 
2.27.0


^ permalink raw reply	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2021-03-02  9:57 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-07-07  9:52 [PATCH] RISC-V: Implment __builtin_thread_pointer Kito Cheng
2020-07-08 19:59 ` Jim Wilson
2020-07-09  6:48   ` Kito Cheng
2020-07-09  6:52     ` Kito Cheng
2021-03-01  8:17   ` Matthias Klose
2021-03-02  9:57     ` Kito Cheng

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