[PATCH] D141268: [LLD] Emit Verbose Asm when using `lto-emit-asm`

[Pierre van Houtryve via Phabricator via llvm-commits]

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D138560 <https://reviews.llvm.org/D138560> was abandonned as the use case can already be covered by `-Xoffload-linker --lto-emit-asm`.
However the output from `--lto-emit-asm` doesn't have
comments like the Clang `-S` output.

This patch adds verbose assembly output to LLD ELF LTO
so that the resulting assembly file more closely matches Clang's.

Having comments is especially important on targets such as AMDGPU because
they contain additional information about the kernel(s) being compiled.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D141268

Files:
  lld/ELF/LTO.cpp
  lld/test/ELF/lto/emit-asm.ll


Index: lld/test/ELF/lto/emit-asm.ll
===================================================================
--- lld/test/ELF/lto/emit-asm.ll
+++ lld/test/ELF/lto/emit-asm.ll
@@ -11,12 +11,16 @@
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-unknown-linux-gnu"
 
+; Note: we also check for the presence of comments; lto-emit-asm output should be verbose.
+
+; CHECK-DAG: # -- Begin function f1
 ; CHECK-DAG: f1:
 ; OPT-DAG: define void @f1()
 define void @f1() {
   ret void
 }
 
+; CHECK-DAG: # -- Begin function f2
 ; CHECK-DAG: f2:
 ; OPT-DAG: define void @f2()
 define void @f2() {
Index: lld/ELF/LTO.cpp
===================================================================
--- lld/ELF/LTO.cpp
+++ lld/ELF/LTO.cpp
@@ -176,8 +176,10 @@
     };
   }
 
-  if (config->ltoEmitAsm)
+  if (config->ltoEmitAsm) {
     c.CGFileType = CGFT_AssemblyFile;
+    c.Options.MCOptions.AsmVerbose = true;
+  }
 
   if (!config->saveTempsArgs.empty())
     checkError(c.addSaveTemps(config->outputFile.str() + ".",


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