From 0113638073ffe734a5fe4ffa1d534c9e044fcb06 Mon Sep 17 00:00:00 2001
From: Nate Begeman <natebegeman@mac.com>
Date: Thu, 18 Nov 2004 04:56:53 +0000
Subject: [PATCH] Clean up and fix cast codegen by removing cases that are
 handled elsewhere, and properly emitting signed short to unsigned int.  This
 fixes the last regression vs. the CBE, MultiSource/Applications/hbd.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@17942 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/PowerPC/PPC32ISelSimple.cpp | 27 ++++++++------------------
 1 file changed, 8 insertions(+), 19 deletions(-)

diff --git a/lib/Target/PowerPC/PPC32ISelSimple.cpp b/lib/Target/PowerPC/PPC32ISelSimple.cpp
index 0e8b7b04c56..2485bcbbebc 100644
--- a/lib/Target/PowerPC/PPC32ISelSimple.cpp
+++ b/lib/Target/PowerPC/PPC32ISelSimple.cpp
@@ -3561,16 +3561,11 @@ void PPC32ISel::emitCastOperation(MachineBasicBlock *MBB,
     // handle { byte, short, int } x { byte, short, int }
     switch (SrcClass) {
     case cByte:
-      if (DestClass == cByte)
-        BuildMI(*MBB, IP, PPC::OR, 2, DestReg).addReg(SrcReg).addReg(SrcReg);
-      else
-        BuildMI(*MBB, IP, PPC::EXTSB, 1, DestReg).addReg(SrcReg);
+      BuildMI(*MBB, IP, PPC::EXTSB, 1, DestReg).addReg(SrcReg);
       break;
     case cShort:
       if (DestClass == cByte)
         BuildMI(*MBB, IP, PPC::EXTSB, 1, DestReg).addReg(SrcReg);
-      else if (DestClass == cShort)
-        BuildMI(*MBB, IP, PPC::OR, 2, DestReg).addReg(SrcReg).addReg(SrcReg);
       else
         BuildMI(*MBB, IP, PPC::EXTSH, 1, DestReg).addReg(SrcReg);
       break;
@@ -3608,19 +3603,13 @@ void PPC32ISel::emitCastOperation(MachineBasicBlock *MBB,
     // handle u{ byte, short, int } -> { byte, short, int }
     switch (SrcClass) {
     case cByte:
-      if (DestClass == cByte)
-        // uByte 255 -> signed byte == -1
-        BuildMI(*MBB, IP, PPC::EXTSB, 1, DestReg).addReg(SrcReg);
-      else
-        // uByte 255 -> signed short/int == 255
-        BuildMI(*MBB, IP, PPC::RLWINM, 4, DestReg).addReg(SrcReg).addImm(0)
-          .addImm(24).addImm(31);
+      // uByte 255 -> signed short/int == 255
+      BuildMI(*MBB, IP, PPC::RLWINM, 4, DestReg).addReg(SrcReg).addImm(0)
+        .addImm(24).addImm(31);
       break;
     case cShort:
       if (DestClass == cByte)
         BuildMI(*MBB, IP, PPC::EXTSB, 1, DestReg).addReg(SrcReg);
-      else if (DestClass == cShort)
-        BuildMI(*MBB, IP, PPC::EXTSH, 1, DestReg).addReg(SrcReg);
       else
         BuildMI(*MBB, IP, PPC::RLWINM, 4, DestReg).addReg(SrcReg).addImm(0)
           .addImm(16).addImm(31);
@@ -3660,14 +3649,14 @@ void PPC32ISel::emitCastOperation(MachineBasicBlock *MBB,
     unsigned clearBits = (DestClass == cByte) ? 24 : 16;
     switch (SrcClass) {
     case cByte:
+       BuildMI(*MBB, IP, PPC::EXTSB, 1, DestReg).addReg(SrcReg);
+       break;
     case cShort:
-      if (DestClass == cByte || DestClass == cShort)
-        // sbyte -1 -> ubyte 0x000000FF
+      if (DestClass == cByte)
         BuildMI(*MBB, IP, PPC::RLWINM, 4, DestReg).addReg(SrcReg)
           .addImm(0).addImm(clearBits).addImm(31);
       else
-        // sbyte -1 -> ubyte 0xFFFFFFFF
-        BuildMI(*MBB, IP, PPC::OR, 2, DestReg).addReg(SrcReg).addReg(SrcReg);
+        BuildMI(*MBB, IP, PPC::EXTSH, 1, DestReg).addReg(SrcReg);
       break;
     case cLong:
       ++SrcReg;