Behold, rlwinm with certain immediate arguments is printed as the much more

readable slwi or srwi (shift left/right word immediate).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@21099 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/PowerPC/PPCAsmPrinter.cpp b/lib/Target/PowerPC/PPCAsmPrinter.cpp
index 025ce9824b39454cb9ec52d2e6256204538efae0..3006f62410336b7c5221380d3db8dd2e2ca98741 100644 (file)
--- a/lib/Target/PowerPC/PPCAsmPrinter.cpp
+++ b/lib/Target/PowerPC/PPCAsmPrinter.cpp
@@ -397,6 +397,28 @@ void PowerPCAsmPrinter::printOp(const MachineOperand &MO, bool IsCallOp) {
 ///
 void PowerPCAsmPrinter::printMachineInstruction(const MachineInstr *MI) {
   ++EmittedInsts;
+  // Check for slwi/srwi mnemonics.
+  if (MI->getOpcode() == PPC::RLWINM) {
+    bool FoundMnemonic = false;
+    unsigned char SH = MI->getOperand(2).getImmedValue();
+    unsigned char MB = MI->getOperand(3).getImmedValue();
+    unsigned char ME = MI->getOperand(4).getImmedValue();
+    if (SH <= 31 && MB == 0 && ME == (31-SH)) {
+      O << "slwi "; FoundMnemonic = true;
+    }
+    if (SH <= 31 && MB == (32-SH) && ME == 31) {
+      O << "srwi "; FoundMnemonic = true;
+      SH = 32-SH;
+    }
+    if (FoundMnemonic) {
+      printOperand(MI, 0, MVT::i64); 
+      O << ", "; 
+      printOperand(MI, 1, MVT::i64); 
+      O << ", " << (unsigned int)SH << "\n";
+      return;
+    }
+  }
+  
   if (printInstruction(MI))
     return; // Printer was automatically generated