Implement unconditional branching support

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@4498 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 20 insertions, 1 deletions

diff --git a/lib/Target/X86/InstSelectSimple.cpp b/lib/Target/X86/InstSelectSimple.cpp
index 144dc228d1..253f3ddcb0 100644
--- a/lib/Target/X86/InstSelectSimple.cpp
+++ b/lib/Target/X86/InstSelectSimple.cpp
@@ -55,6 +55,7 @@ namespace {
     // fixed X86 code for each instruction.
     //
     void visitReturnInst(ReturnInst &RI);
+    void visitBranchInst(BranchInst &BI);
     void visitAdd(BinaryOperator &B);
     void visitShiftInst(ShiftInst &I);
 
@@ -162,6 +163,14 @@ void ISel::visitReturnInst(ReturnInst &I) {
   BuildMI(BB, X86::RET, 0);
 }
 
+void ISel::visitBranchInst(BranchInst &BI) {
+  if (BI.isConditional())   // Only handles unconditional branches so far...
+    visitInstruction(BI);
+
+  BuildMI(BB, X86::JMP, 1).addPCDisp(BI.getSuccessor(0));
+}
+
+
 /// Shift instructions: 'shl', 'sar', 'shr' - Some special cases here
 /// for constant immediate shift values, and for constant immediate
 /// shift values equal to 1. Even the general case is sort of special,
diff --git a/lib/Target/X86/X86ISelSimple.cpp b/lib/Target/X86/X86ISelSimple.cpp
index 144dc228d1..253f3ddcb0 100644
--- a/lib/Target/X86/X86ISelSimple.cpp
+++ b/lib/Target/X86/X86ISelSimple.cpp
@@ -55,6 +55,7 @@ namespace {
     // fixed X86 code for each instruction.
     //
     void visitReturnInst(ReturnInst &RI);
+    void visitBranchInst(BranchInst &BI);
     void visitAdd(BinaryOperator &B);
     void visitShiftInst(ShiftInst &I);
 
@@ -162,6 +163,14 @@ void ISel::visitReturnInst(ReturnInst &I) {
   BuildMI(BB, X86::RET, 0);
 }
 
+void ISel::visitBranchInst(BranchInst &BI) {
+  if (BI.isConditional())   // Only handles unconditional branches so far...
+    visitInstruction(BI);
+
+  BuildMI(BB, X86::JMP, 1).addPCDisp(BI.getSuccessor(0));
+}
+
+
 /// Shift instructions: 'shl', 'sar', 'shr' - Some special cases here
 /// for constant immediate shift values, and for constant immediate
 /// shift values equal to 1. Even the general case is sort of special,
diff --git a/lib/Target/X86/X86InstrInfo.def b/lib/Target/X86/X86InstrInfo.def
index 519e7680d7..327c4e64f6 100644
--- a/lib/Target/X86/X86InstrInfo.def
+++ b/lib/Target/X86/X86InstrInfo.def
@@ -33,8 +33,9 @@ I(PHI         , "phi",                0, 0)
 // The second instruction must always be the noop instruction: (FIXME, not yet)
 I(NOOP        , "nop",                0, X86II::Void) // nop          90
 
-// Miscellaneous instructions
+// Flow control instructions
 I(RET         , "ret",       M_RET_FLAG, X86II::Void) // ret          CB
+I(JMP         , "jmp",    M_BRANCH_FLAG, X86II::Void) // jmp foo      EB|E9 cb|w
 
 // Move instructions
 I(MOVrr8      , "movb",               0, 0)           // R8  = R8     88/r