[AMDGPU] Don't suppress printing the .l and .h register suffixes.

We don't seem to have a use for the -amdgpu-keep-16-bit-reg-suffixes
option anymore. Was introduced in <https://reviews.llvm.org/D79435>.

Reviewed By: Joe_Nash, foad

Differential Revision: https://reviews.llvm.org/D156102

Author: kosarev

llvm/lib/Target/AMDGPU/MCTargetDesc/AMDGPUInstPrinter.cpp

@@ -24,12 +24,6 @@
 using namespace llvm;
 using namespace llvm::AMDGPU;
 
-static cl::opt<bool> Keep16BitSuffixes(
-  "amdgpu-keep-16-bit-reg-suffixes",
-  cl::desc("Keep .l and .h suffixes in asm for debugging purposes"),
-  cl::init(false),
-  cl::ReallyHidden);
-
 void AMDGPUInstPrinter::printRegName(raw_ostream &OS, MCRegister Reg) const {
   // FIXME: The current implementation of
   // AsmParser::parseRegisterOrRegisterNumber in MC implies we either emit this
@@ -278,12 +272,7 @@ void AMDGPUInstPrinter::printRegOperand(unsigned RegNo, raw_ostream &O,
   }
 #endif
 
-  StringRef RegName(getRegisterName(RegNo));
-  if (!Keep16BitSuffixes)
-    if (!RegName.consume_back(".l"))
-      RegName.consume_back(".h");
-
-  O << RegName;
+  O << getRegisterName(RegNo);
 }
 
 void AMDGPUInstPrinter::printVOPDst(const MCInst *MI, unsigned OpNo,

llvm/test/CodeGen/AMDGPU/lo16-hi16-illegal-copy.mir

@@ -1,7 +1,7 @@
-# RUN: not llc -march=amdgcn -mcpu=gfx802 -start-before postrapseudos -asm-verbose=0 -amdgpu-keep-16-bit-reg-suffixes -verify-machineinstrs %s -o - 2>&1 | FileCheck -check-prefixes=ERR,GFX8-ERR %s
-# RUN: not llc -march=amdgcn -mcpu=gfx802 -start-before postrapseudos -asm-verbose=0 -amdgpu-keep-16-bit-reg-suffixes -verify-machineinstrs %s -o - 2>&1 | FileCheck -check-prefix=GCN %s
-# RUN: not llc -march=amdgcn -mcpu=gfx900 -start-before postrapseudos -asm-verbose=0 -amdgpu-keep-16-bit-reg-suffixes -verify-machineinstrs %s -o - 2>&1 | FileCheck -check-prefix=ERR %s
-# RUN: not llc -march=amdgcn -mcpu=gfx900 -start-before postrapseudos -asm-verbose=0 -amdgpu-keep-16-bit-reg-suffixes -verify-machineinstrs %s -o - 2>&1 | FileCheck -check-prefixes=GCN,GFX9 %s
+# RUN: not llc -march=amdgcn -mcpu=gfx802 -start-before postrapseudos -asm-verbose=0 -verify-machineinstrs %s -o - 2>&1 | FileCheck -check-prefixes=ERR,GFX8-ERR %s
+# RUN: not llc -march=amdgcn -mcpu=gfx802 -start-before postrapseudos -asm-verbose=0 -verify-machineinstrs %s -o - 2>&1 | FileCheck -check-prefix=GCN %s
+# RUN: not llc -march=amdgcn -mcpu=gfx900 -start-before postrapseudos -asm-verbose=0 -verify-machineinstrs %s -o - 2>&1 | FileCheck -check-prefix=ERR %s
+# RUN: not llc -march=amdgcn -mcpu=gfx900 -start-before postrapseudos -asm-verbose=0 -verify-machineinstrs %s -o - 2>&1 | FileCheck -check-prefixes=GCN,GFX9 %s
 
 # Note: GFX8 did not allow SDWA SGPR sources. Therefor no HI16 subregs can be used there.