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
