Added the definitions for one-bit left shifts to

the Intel instruction tables.

The patterns will stay blank because ADD reg, reg
is faster, but having the encoding available is
useful for the disassembler.

llvm-svn: 81994

2 files changed, 15 insertions, 4 deletions

diff --git a/llvm/lib/Target/X86/X86Instr64bit.td b/llvm/lib/Target/X86/X86Instr64bit.td
index dc98a2e3099..6f7b6fd4037 100644
--- a/llvm/lib/Target/X86/X86Instr64bit.td
+++ b/llvm/lib/Target/X86/X86Instr64bit.td
@@ -752,8 +752,10 @@ let isConvertibleToThreeAddress = 1 in   // Can transform into LEA.
 def SHL64ri  : RIi8<0xC1, MRM4r, (outs GR64:$dst), (ins GR64:$src1, i8imm:$src2),
                     "shl{q}\t{$src2, $dst|$dst, $src2}",
                     [(set GR64:$dst, (shl GR64:$src1, (i8 imm:$src2)))]>;
-// NOTE: We don't use shifts of a register by one, because 'add reg,reg' is
-// cheaper.
+// NOTE: We don't include patterns for shifts of a register by one, because
+// 'add reg,reg' is cheaper.
+def SHL64r1  : RI<0xD1, MRM4r, (outs GR64:$dst), (ins GR64:$src1),
+                 "shr{q}\t$dst", []>;
 } // isTwoAddress
 
 let Uses = [CL] in
diff --git a/llvm/lib/Target/X86/X86InstrInfo.td b/llvm/lib/Target/X86/X86InstrInfo.td
index d988406b637..e310e646e7e 100644
--- a/llvm/lib/Target/X86/X86InstrInfo.td
+++ b/llvm/lib/Target/X86/X86InstrInfo.td
@@ -1974,8 +1974,17 @@ def SHL16ri  : Ii8<0xC1, MRM4r, (outs GR16:$dst), (ins GR16:$src1, i8imm:$src2),
 def SHL32ri  : Ii8<0xC1, MRM4r, (outs GR32:$dst), (ins GR32:$src1, i8imm:$src2),
                    "shl{l}\t{$src2, $dst|$dst, $src2}",
                    [(set GR32:$dst, (shl GR32:$src1, (i8 imm:$src2)))]>;
-// NOTE: We don't use shifts of a register by one, because 'add reg,reg' is
-// cheaper.
+
+// NOTE: We don't include patterns for shifts of a register by one, because
+// 'add reg,reg' is cheaper.
+
+def SHL8r1   : I<0xD0, MRM4r, (outs GR8:$dst), (ins GR8:$src1),
+                 "shl{b}\t$dst", []>;
+def SHL16r1  : I<0xD1, MRM4r, (outs GR16:$dst), (ins GR16:$src1),
+                 "shl{w}\t$dst", []>, OpSize;
+def SHL32r1  : I<0xD1, MRM4r, (outs GR32:$dst), (ins GR32:$src1),
+                 "shl{l}\t$dst", []>;
+
 } // isConvertibleToThreeAddress = 1
 
 let isTwoAddress = 0 in {