[llvm-commits] [llvm] r104120 - in /llvm/trunk/lib/Target/X86: AsmPrinter/X86MCInstLower.cpp X86InstrInfo.td

[Daniel Dunbar]

Author: ddunbar
Date: Wed May 19 10:26:43 2010
New Revision: 104120

URL: http://llvm.org/viewvc/llvm-project?rev=104120&view=rev
Log:
MC/X86: Lower TAILCALLd[64] to JMP_1, to allow relaxation and to avoid same
prefix byte problem as in r104062.
 - As a total hack to keep the TAILCALL markers in the output, which some tests depend on, this invents a new TAILJMP_1 instruction.

Modified:
    llvm/trunk/lib/Target/X86/AsmPrinter/X86MCInstLower.cpp
    llvm/trunk/lib/Target/X86/X86InstrInfo.td

Modified: llvm/trunk/lib/Target/X86/AsmPrinter/X86MCInstLower.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/AsmPrinter/X86MCInstLower.cpp?rev=104120&r1=104119&r2=104120&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/AsmPrinter/X86MCInstLower.cpp (original)
+++ llvm/trunk/lib/Target/X86/AsmPrinter/X86MCInstLower.cpp Wed May 19 10:26:43 2010
@@ -379,6 +379,16 @@
     break;
   }
 
+  // TAILJMPd, TAILJMPd64 - Lower to the correct jump instructions.
+  case X86::TAILJMPd:
+  case X86::TAILJMPd64: {
+    MCOperand Saved = OutMI.getOperand(0);
+    OutMI = MCInst();
+    OutMI.setOpcode(X86::TAILJMP_1);
+    OutMI.addOperand(Saved);
+    break;
+  }
+
   // The assembler backend wants to see branches in their small form and relax
   // them to their large form.  The JIT can only handle the large form because
   // it does not do relaxation.  For now, translate the large form to the

Modified: llvm/trunk/lib/Target/X86/X86InstrInfo.td
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86InstrInfo.td?rev=104120&r1=104119&r2=104120&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86InstrInfo.td (original)
+++ llvm/trunk/lib/Target/X86/X86InstrInfo.td Wed May 19 10:26:43 2010
@@ -712,6 +712,13 @@
   let mayLoad = 1 in
   def TAILJMPm : I<0xFF, MRM4m, (outs), (ins i32mem_TC:$dst, variable_ops),
                    "jmp{l}\t{*}$dst  # TAILCALL", []>;
+
+  // FIXME: This is a hack so that MCInst lowering can preserve the TAILCALL
+  // marker on instructions, while still being able to relax.
+  let isCodeGenOnly = 1 in {
+    def TAILJMP_1 : Ii8PCRel<0xEB, RawFrm, (outs), (ins brtarget8:$dst),
+                         "jmp\t$dst  # TAILCALL", []>;
+  }
 }
 
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