[AMDGPU] Add pal metadata 3.0 support to callable pal funcs (#67104)

PAL Metadata 3.0 introduces an explicit structure in metadata for the programmable registers written out by the compiler backend. The previous approach used opaque registers which can change between different architectures and required encoding the bitfield information in the backend, which may change between versions. This change is an extension the previously added support - which only handled entry functions. This adds support for all functions. The change also includes some re-factoring to separate common code.
llvm · Feb 6, 2024 · d6c7253 · d6c7253
1 parent d4c5aca
commit d6c7253
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Showing 4 changed files with 347 additions and 22 deletions.
diff --git a/llvm/lib/Target/AMDGPU/AMDGPUAsmPrinter.cpp b/llvm/lib/Target/AMDGPU/AMDGPUAsmPrinter.cpp
@@ -1025,6 +1025,27 @@ void AMDGPUAsmPrinter::EmitProgramInfoSI(const MachineFunction &MF,
   OutStreamer->emitInt32(MFI->getNumSpilledVGPRs());
 }
 
+// Helper function to add common PAL Metadata 3.0+
+static void EmitPALMetadataCommon(AMDGPUPALMetadata *MD,
+                                  const SIProgramInfo &CurrentProgramInfo,
+                                  CallingConv::ID CC, const GCNSubtarget &ST) {
+  if (ST.hasIEEEMode())
+    MD->setHwStage(CC, ".ieee_mode", (bool)CurrentProgramInfo.IEEEMode);
+
+  MD->setHwStage(CC, ".wgp_mode", (bool)CurrentProgramInfo.WgpMode);
+  MD->setHwStage(CC, ".mem_ordered", (bool)CurrentProgramInfo.MemOrdered);
+
+  if (AMDGPU::isCompute(CC)) {
+    MD->setHwStage(CC, ".trap_present",
+                   (bool)CurrentProgramInfo.TrapHandlerEnable);
+    MD->setHwStage(CC, ".excp_en", CurrentProgramInfo.EXCPEnable);
+
+    MD->setHwStage(CC, ".lds_size",
+                   (unsigned)(CurrentProgramInfo.LdsSize *
+                              getLdsDwGranularity(ST) * sizeof(uint32_t)));
+  }
+}
+
 // This is the equivalent of EmitProgramInfoSI above, but for when the OS type
 // is AMDPAL.  It stores each compute/SPI register setting and other PAL
 // metadata items into the PALMD::Metadata, combining with any provided by the
@@ -1056,24 +1077,8 @@ void AMDGPUAsmPrinter::EmitPALMetadata(const MachineFunction &MF,
     }
   } else {
     MD->setHwStage(CC, ".debug_mode", (bool)CurrentProgramInfo.DebugMode);
-    MD->setHwStage(CC, ".ieee_mode", (bool)CurrentProgramInfo.IEEEMode);
-    MD->setHwStage(CC, ".wgp_mode", (bool)CurrentProgramInfo.WgpMode);
-    MD->setHwStage(CC, ".mem_ordered", (bool)CurrentProgramInfo.MemOrdered);
-
-    if (AMDGPU::isCompute(CC)) {
-      MD->setHwStage(CC, ".scratch_en", (bool)CurrentProgramInfo.ScratchEnable);
-      MD->setHwStage(CC, ".trap_present",
-                     (bool)CurrentProgramInfo.TrapHandlerEnable);
-
-      // EXCPEnMSB?
-      const unsigned LdsDwGranularity = 128;
-      MD->setHwStage(CC, ".lds_size",
-                     (unsigned)(CurrentProgramInfo.LdsSize * LdsDwGranularity *
-                                sizeof(uint32_t)));
-      MD->setHwStage(CC, ".excp_en", CurrentProgramInfo.EXCPEnable);
-    } else {
-      MD->setHwStage(CC, ".scratch_en", (bool)CurrentProgramInfo.ScratchEnable);
-    }
+    MD->setHwStage(CC, ".scratch_en", (bool)CurrentProgramInfo.ScratchEnable);
+    EmitPALMetadataCommon(MD, CurrentProgramInfo, CC, STM);
   }
 
   // ScratchSize is in bytes, 16 aligned.
@@ -1127,10 +1132,15 @@ void AMDGPUAsmPrinter::emitPALFunctionMetadata(const MachineFunction &MF) {
   MD->setFunctionScratchSize(FnName, MFI.getStackSize());
   const GCNSubtarget &ST = MF.getSubtarget<GCNSubtarget>();
 
-  // Set compute registers
-  MD->setRsrc1(CallingConv::AMDGPU_CS,
-               CurrentProgramInfo.getPGMRSrc1(CallingConv::AMDGPU_CS, ST));
-  MD->setRsrc2(CallingConv::AMDGPU_CS, CurrentProgramInfo.getComputePGMRSrc2());
+  if (MD->getPALMajorVersion() < 3) {
+    // Set compute registers
+    MD->setRsrc1(CallingConv::AMDGPU_CS,
+                 CurrentProgramInfo.getPGMRSrc1(CallingConv::AMDGPU_CS, ST));
+    MD->setRsrc2(CallingConv::AMDGPU_CS,
+                 CurrentProgramInfo.getComputePGMRSrc2());
+  } else {
+    EmitPALMetadataCommon(MD, CurrentProgramInfo, CallingConv::AMDGPU_CS, ST);
+  }
 
   // Set optional info
   MD->setFunctionLdsSize(FnName, CurrentProgramInfo.LDSSize);

diff --git a/llvm/lib/Target/AMDGPU/Utils/AMDGPUBaseInfo.cpp b/llvm/lib/Target/AMDGPU/Utils/AMDGPUBaseInfo.cpp
@@ -2958,6 +2958,11 @@ bool isDPALU_DPP(const MCInstrDesc &OpDesc) {
   return hasAny64BitVGPROperands(OpDesc);
 }
 
+unsigned getLdsDwGranularity(const MCSubtargetInfo &ST) {
+  // Currently this is 128 for all subtargets
+  return 128;
+}
+
 } // namespace AMDGPU
 
 raw_ostream &operator<<(raw_ostream &OS,

diff --git a/llvm/lib/Target/AMDGPU/Utils/AMDGPUBaseInfo.h b/llvm/lib/Target/AMDGPU/Utils/AMDGPUBaseInfo.h
@@ -1439,6 +1439,11 @@ bool isIntrinsicSourceOfDivergence(unsigned IntrID);
 /// \returns true if the intrinsic is uniform
 bool isIntrinsicAlwaysUniform(unsigned IntrID);
 
+/// \returns lds block size in terms of dwords. \p
+/// This is used to calculate the lds size encoded for PAL metadata 3.0+ which
+/// must be defined in terms of bytes.
+unsigned getLdsDwGranularity(const MCSubtargetInfo &ST);
+
 } // end namespace AMDGPU
 
 raw_ostream &operator<<(raw_ostream &OS,