commit a951f77ca31b43551bd41765504519d6d76e6cbf
author Devang Patel <dpatel@apple.com> Thu Jan 19 18:40:55 2012 +0000
committer Devang Patel <dpatel@apple.com> Thu Jan 19 18:40:55 2012 +0000
tree e7ab306afa704156780526564cb24511b0e10992
parent f460bf8cd8e8a711e9de33085884e31d1c989010

Post process 'and', 'sub' instructions and select better encoding, if available.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@148489 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/X86/AsmParser/X86AsmParser.cpp

diff --git a/lib/Target/X86/AsmParser/X86AsmParser.cpp b/lib/Target/X86/AsmParser/X86AsmParser.cpp
index 1763419..67c4a64 100644
--- a/lib/Target/X86/AsmParser/X86AsmParser.cpp
+++ b/lib/Target/X86/AsmParser/X86AsmParser.cpp
@@ -1331,6 +1331,84 @@
     Inst = TmpInst;
     return true;
   }
+  case X86::ADD16i16: {
+    if (!Inst.getOperand(0).isImm() ||
+        !isImmSExti16i8Value(Inst.getOperand(0).getImm()))
+      return false;
+
+    MCInst TmpInst;
+    TmpInst.setOpcode(X86::ADD16ri8);
+    TmpInst.addOperand(MCOperand::CreateReg(X86::AX));
+    TmpInst.addOperand(MCOperand::CreateReg(X86::AX));
+    TmpInst.addOperand(Inst.getOperand(0));
+    Inst = TmpInst;
+    return true;
+  }
+  case X86::ADD32i32: {
+    if (!Inst.getOperand(0).isImm() ||
+        !isImmSExti32i8Value(Inst.getOperand(0).getImm()))
+      return false;
+
+    MCInst TmpInst;
+    TmpInst.setOpcode(X86::ADD32ri8);
+    TmpInst.addOperand(MCOperand::CreateReg(X86::EAX));
+    TmpInst.addOperand(MCOperand::CreateReg(X86::EAX));
+    TmpInst.addOperand(Inst.getOperand(0));
+    Inst = TmpInst;
+    return true;
+  }
+  case X86::ADD64i32: {
+    if (!Inst.getOperand(0).isImm() ||
+        !isImmSExti64i8Value(Inst.getOperand(0).getImm()))
+      return false;
+
+    MCInst TmpInst;
+    TmpInst.setOpcode(X86::ADD64ri8);
+    TmpInst.addOperand(MCOperand::CreateReg(X86::RAX));
+    TmpInst.addOperand(MCOperand::CreateReg(X86::RAX));
+    TmpInst.addOperand(Inst.getOperand(0));
+    Inst = TmpInst;
+    return true;
+  }
+  case X86::SUB16i16: {
+    if (!Inst.getOperand(0).isImm() ||
+        !isImmSExti16i8Value(Inst.getOperand(0).getImm()))
+      return false;
+
+    MCInst TmpInst;
+    TmpInst.setOpcode(X86::SUB16ri8);
+    TmpInst.addOperand(MCOperand::CreateReg(X86::AX));
+    TmpInst.addOperand(MCOperand::CreateReg(X86::AX));
+    TmpInst.addOperand(Inst.getOperand(0));
+    Inst = TmpInst;
+    return true;
+  }
+  case X86::SUB32i32: {
+    if (!Inst.getOperand(0).isImm() ||
+        !isImmSExti32i8Value(Inst.getOperand(0).getImm()))
+      return false;
+
+    MCInst TmpInst;
+    TmpInst.setOpcode(X86::SUB32ri8);
+    TmpInst.addOperand(MCOperand::CreateReg(X86::EAX));
+    TmpInst.addOperand(MCOperand::CreateReg(X86::EAX));
+    TmpInst.addOperand(Inst.getOperand(0));
+    Inst = TmpInst;
+    return true;
+  }
+  case X86::SUB64i32: {
+    if (!Inst.getOperand(0).isImm() ||
+        !isImmSExti64i8Value(Inst.getOperand(0).getImm()))
+      return false;
+
+    MCInst TmpInst;
+    TmpInst.setOpcode(X86::SUB64ri8);
+    TmpInst.addOperand(MCOperand::CreateReg(X86::RAX));
+    TmpInst.addOperand(MCOperand::CreateReg(X86::RAX));
+    TmpInst.addOperand(Inst.getOperand(0));
+    Inst = TmpInst;
+    return true;
+  }
   }
   return false;
 }

test/MC/X86/intel-syntax-encoding.s

diff --git a/test/MC/X86/intel-syntax-encoding.s b/test/MC/X86/intel-syntax-encoding.s
index 23eff01..c81636b 100644
--- a/test/MC/X86/intel-syntax-encoding.s
+++ b/test/MC/X86/intel-syntax-encoding.s
@@ -24,3 +24,11 @@
 // CHECK: encoding: [0x48,0x89,0x44,0x24,0xf0]	
 	mov	QWORD PTR [RSP - 16], RAX
 
+// CHECK: encoding: [0x66,0x83,0xc0,0xf4]
+	add	ax, -12
+// CHECK: encoding: [0x83,0xc0,0xf4]
+	add	eax, -12
+// CHECK: encoding: [0x48,0x83,0xc0,0xf4]
+	add	rax, -12
+
+