openmp: Add -foffload-memory

https://patchwork.sourceware.org/project/gcc/list/?series=35022

Add a new option.  It's inactive until I add some follow-up patches.

gcc/ChangeLog:

	* common.opt: Add -foffload-memory and its enum values.
	* coretypes.h (enum offload_memory): New.
	* doc/invoke.texi: Document -foffload-memory.

3 files changed, 38 insertions, 0 deletions

diff --git a/gcc/common.opt b/gcc/common.opt
index e3fa0da..c3bbadd 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -2423,6 +2423,22 @@ foffload-abi-host-opts=
 Common Joined MissingArgError(option missing after %qs)
 -foffload-abi-host-opts=<options>	Specify host ABI options.
 
+foffload-memory=
+Common Joined RejectNegative Enum(offload_memory) Var(flag_offload_memory) Init(OFFLOAD_MEMORY_NONE)
+-foffload-memory=[none|unified|pinned]	Use an offload memory optimization.
+
+Enum
+Name(offload_memory) Type(enum offload_memory) UnknownError(Unknown offload memory option %qs)
+
+EnumValue
+Enum(offload_memory) String(none) Value(OFFLOAD_MEMORY_NONE)
+
+EnumValue
+Enum(offload_memory) String(unified) Value(OFFLOAD_MEMORY_UNIFIED)
+
+EnumValue
+Enum(offload_memory) String(pinned) Value(OFFLOAD_MEMORY_PINNED)
+
 fomit-frame-pointer
 Common Var(flag_omit_frame_pointer) Optimization
 When possible do not generate stack frames.
diff --git a/gcc/coretypes.h b/gcc/coretypes.h
index a11ebd1..3d483a5 100644
--- a/gcc/coretypes.h
+++ b/gcc/coretypes.h
@@ -228,6 +228,13 @@ enum offload_abi {
   OFFLOAD_ABI_ILP32
 };
 
+/* Types of memory optimization for an offload device.  */
+enum offload_memory {
+  OFFLOAD_MEMORY_NONE,
+  OFFLOAD_MEMORY_UNIFIED,
+  OFFLOAD_MEMORY_PINNED
+};
+
 /* Types of profile update methods.  */
 enum profile_update {
   PROFILE_UPDATE_SINGLE,
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index f55f789..3135821 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -302,6 +302,7 @@ Objective-C and Objective-C++ Dialects}.
 @item OpenMP and OpenACC Options
 @xref{OpenMP and OpenACC Options,,Options Controlling OpenMP and OpenACC}.
 @gccoptlist{-foffload=@var{arg}  -foffload-options=@var{arg}
+-foffload-memory=@var{arg}
 -fopenacc  -fopenacc-dim=@var{geom}
 -fopenmp  -fopenmp-simd  -fopenmp-target-simd-clone@r{[}=@var{device-type}@r{]}}
 
@@ -5235,6 +5236,20 @@ Typical command lines are
 -foffload-options=amdgcn-amdhsa=-march=gfx906
 @end smallexample
 
+@opindex foffload-memory
+@cindex OpenMP offloading memory modes
+@item -foffload-memory=none
+@itemx -foffload-memory=unified
+@itemx -foffload-memory=pinned
+Enable a memory optimization mode to use with OpenMP.  The default behavior,
+@option{-foffload-memory=none}, is to do nothing special (unless enabled via
+a requires directive in the code).  @option{-foffload-memory=unified} is
+equivalent to @code{#pragma omp requires unified_shared_memory}.
+@option{-foffload-memory=pinned} forces all host memory to be pinned (this
+mode may require the user to increase the ulimit setting for locked memory).
+All translation units must select the same setting to avoid undefined
+behavior.
+
 @opindex fopenacc
 @cindex OpenACC accelerator programming
 @item -fopenacc