[llvm] af5e61b - [NVPTX] Fix for NVPTX module asm regression

[Artem Belevich via llvm-commits]

Author: tatz.j at northeastern.edu
Date: 2020-06-24T11:17:09-07:00
New Revision: af5e61bf4fd1bf865f90beab0227ff4901246eeb

URL: https://github.com/llvm/llvm-project/commit/af5e61bf4fd1bf865f90beab0227ff4901246eeb
DIFF: https://github.com/llvm/llvm-project/commit/af5e61bf4fd1bf865f90beab0227ff4901246eeb.diff

LOG: [NVPTX] Fix for NVPTX module asm regression

Currently module asm ends up emitted twice and at the wrong place in the PTX.
This patch moves module asm generation into emitStartOfAsmFile() which puts at
the correct location in the generated PTX.

Differential Revision: https://reviews.llvm.org/D82280

Added: 
    

Modified: 
    llvm/lib/Target/NVPTX/NVPTXAsmPrinter.cpp
    llvm/lib/Target/NVPTX/NVPTXAsmPrinter.h
    llvm/test/CodeGen/NVPTX/module-inline-asm.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/NVPTX/NVPTXAsmPrinter.cpp b/llvm/lib/Target/NVPTX/NVPTXAsmPrinter.cpp
index c68ac5cd024a..da1a398a68f0 100644
--- a/llvm/lib/Target/NVPTX/NVPTXAsmPrinter.cpp
+++ b/llvm/lib/Target/NVPTX/NVPTXAsmPrinter.cpp
@@ -762,13 +762,21 @@ static bool isEmptyXXStructor(GlobalVariable *GV) {
   return InitList->getNumOperands() == 0;
 }
 
-bool NVPTXAsmPrinter::doInitialization(Module &M) {
+void NVPTXAsmPrinter::emitStartOfAsmFile(Module &M) {
   // Construct a default subtarget off of the TargetMachine defaults. The
   // rest of NVPTX isn't friendly to change subtargets per function and
   // so the default TargetMachine will have all of the options.
   const NVPTXTargetMachine &NTM = static_cast<const NVPTXTargetMachine &>(TM);
   const auto* STI = static_cast<const NVPTXSubtarget*>(NTM.getSubtargetImpl());
+  SmallString<128> Str1;
+  raw_svector_ostream OS1(Str1);
 
+  // Emit header before any dwarf directives are emitted below.
+  emitHeader(M, OS1, *STI);
+  OutStreamer->emitRawText(OS1.str());
+}
+
+bool NVPTXAsmPrinter::doInitialization(Module &M) {
   if (M.alias_size()) {
     report_fatal_error("Module has aliases, which NVPTX does not support.");
     return true; // error
@@ -784,26 +792,9 @@ bool NVPTXAsmPrinter::doInitialization(Module &M) {
     return true;  // error
   }
 
-  SmallString<128> Str1;
-  raw_svector_ostream OS1(Str1);
-
   // We need to call the parent's one explicitly.
   bool Result = AsmPrinter::doInitialization(M);
 
-  // Emit header before any dwarf directives are emitted below.
-  emitHeader(M, OS1, *STI);
-  OutStreamer->emitRawText(OS1.str());
-
-  // Emit module-level inline asm if it exists.
-  if (!M.getModuleInlineAsm().empty()) {
-    OutStreamer->AddComment("Start of file scope inline assembly");
-    OutStreamer->AddBlankLine();
-    OutStreamer->emitRawText(StringRef(M.getModuleInlineAsm()));
-    OutStreamer->AddBlankLine();
-    OutStreamer->AddComment("End of file scope inline assembly");
-    OutStreamer->AddBlankLine();
-  }
-
   GlobalsEmitted = false;
 
   return Result;

diff  --git a/llvm/lib/Target/NVPTX/NVPTXAsmPrinter.h b/llvm/lib/Target/NVPTX/NVPTXAsmPrinter.h
index ae2731b025cc..5c3a4eb470c1 100644
--- a/llvm/lib/Target/NVPTX/NVPTXAsmPrinter.h
+++ b/llvm/lib/Target/NVPTX/NVPTXAsmPrinter.h
@@ -200,6 +200,7 @@ class LLVM_LIBRARY_VISIBILITY NVPTXAsmPrinter : public AsmPrinter {
   const Function *F;
   std::string CurrentFnName;
 
+  void emitStartOfAsmFile(Module &M) override;
   void emitBasicBlockStart(const MachineBasicBlock &MBB) override;
   void emitFunctionEntryLabel() override;
   void emitFunctionBodyStart() override;

diff  --git a/llvm/test/CodeGen/NVPTX/module-inline-asm.ll b/llvm/test/CodeGen/NVPTX/module-inline-asm.ll
index cdbcf2013c00..a2ce6a7f87b3 100644
--- a/llvm/test/CodeGen/NVPTX/module-inline-asm.ll
+++ b/llvm/test/CodeGen/NVPTX/module-inline-asm.ll
@@ -2,9 +2,19 @@
 
 target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v16:16:16-v32:32:32-v64:64:64-v128:128:128-n16:32:64"
 
+; module asm must come after PTX version/target directives.
+; CHECK-NOT: .global .b32 val;
+
+; CHECK-DAG: .version
+; CHECK-DAG: .target
+
 ; CHECK: .global .b32 val;
 module asm ".global .b32 val;"
 
+; module asm must happen before we emit other things.
+; CHECK-LABEL: .visible .func foo
 define void @foo() {
   ret void
 }
+; Make sure it does not show up anywhere else in the output.
+; CHECK-NOT: .global .b32 val;