AMDGPU/SI: Add new target attribute InitialPSInputAddr
Summary:
This allows Mesa to pass initial SPI_PS_INPUT_ADDR to LLVM.
The register assigns VGPR locations to PS inputs, while the ENA register
determines whether or not they are loaded.
Mesa needs to set some inputs as not-movable, so that a pixel shader prolog
binary appended at the beginning can assume where some inputs are.
v2: Make PSInputAddr private, because there is never enough silly getters
and setters for people to read.
Reviewers: tstellarAMD, arsenm
Subscribers: arsenm
Differential Revision: http://reviews.llvm.org/D16030
llvm-svn: 257591
diff --git a/llvm/lib/Target/AMDGPU/SIISelLowering.cpp b/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
index c251752..5959afb 100644
--- a/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
+++ b/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
@@ -601,14 +601,18 @@
assert((PSInputNum <= 15) && "Too many PS inputs!");
- if (!Arg.Used) {
+ if (!Arg.Used && !Info->isPSInputAllocated(PSInputNum)) {
// We can safely skip PS inputs
Skipped.set(i);
++PSInputNum;
continue;
}
- Info->PSInputAddr |= 1 << PSInputNum++;
+ Info->markPSInputAllocated(PSInputNum);
+ if (Arg.Used)
+ Info->PSInputEna |= 1 << PSInputNum;
+
+ ++PSInputNum;
}
// Second split vertices into their elements
@@ -638,11 +642,18 @@
*DAG.getContext());
// At least one interpolation mode must be enabled or else the GPU will hang.
+ //
+ // Check PSInputAddr instead of PSInputEna. The idea is that if the user set
+ // PSInputAddr, the user wants to enable some bits after the compilation
+ // based on run-time states. Since we can't know what the final PSInputEna
+ // will look like, so we shouldn't do anything here and the user should take
+ // responsibility for the correct programming.
if (Info->getShaderType() == ShaderType::PIXEL &&
- (Info->PSInputAddr & 0x7F) == 0) {
- Info->PSInputAddr |= 1;
+ (Info->getPSInputAddr() & 0x7F) == 0) {
CCInfo.AllocateReg(AMDGPU::VGPR0);
CCInfo.AllocateReg(AMDGPU::VGPR1);
+ Info->markPSInputAllocated(0);
+ Info->PSInputEna |= 1;
}
if (Info->getShaderType() == ShaderType::COMPUTE) {