[AMDGPU] AMDPAL scratch buffer support
Summary:
Added support for scratch (including spilling) for OS type amdpal:
generates code to set up the scratch descriptor if it is needed.
With amdpal, the scratch resource descriptor is loaded from offset 0 of
the global information table. The low 32 bits of the address of the
global information table is passed in s0.
Added amdgpu-git-ptr-high function attribute to hard-wire the high 32
bits of the address of the global information table. If the function
attribute is not specified, or is 0xffffffff, then the backend generates
code to use the high 32 bits of pc.
The documentation for the AMDPAL ABI will be added in a later commit.
Subscribers: arsenm, kzhuravl, wdng, nhaehnle, yaxunl, dstuttard, t-tye
Differential Revision: https://reviews.llvm.org/D37483
llvm-svn: 314501
diff --git a/llvm/lib/Target/AMDGPU/SIMachineFunctionInfo.h b/llvm/lib/Target/AMDGPU/SIMachineFunctionInfo.h
index 242b41a..ade909cc 100644
--- a/llvm/lib/Target/AMDGPU/SIMachineFunctionInfo.h
+++ b/llvm/lib/Target/AMDGPU/SIMachineFunctionInfo.h
@@ -185,6 +185,11 @@
// user arguments. This is an offset from the KernargSegmentPtr.
bool ImplicitArgPtr : 1;
+ // The hard-wired high half of the address of the global information table
+ // for AMDPAL OS type. 0xffffffff represents no hard-wired high half, since
+ // current hardware only allows a 16 bit value.
+ unsigned GITPtrHigh;
+
MCPhysReg getNextUserSGPR() const {
assert(NumSystemSGPRs == 0 && "System SGPRs must be added after user SGPRs");
return AMDGPU::SGPR0 + NumUserSGPRs;
@@ -406,6 +411,10 @@
return ArgInfo.getPreloadedValue(Value).first->getRegister();
}
+ unsigned getGITPtrHigh() const {
+ return GITPtrHigh;
+ }
+
unsigned getNumUserSGPRs() const {
return NumUserSGPRs;
}