Add RORX code generation support

llvm-svn: 164674

2 files changed, 27 insertions, 0 deletions

diff --git a/llvm/lib/Target/X86/X86InstrInfo.cpp b/llvm/lib/Target/X86/X86InstrInfo.cpp
index f575e801844..2fb2ed2104c 100644
--- a/llvm/lib/Target/X86/X86InstrInfo.cpp
+++ b/llvm/lib/Target/X86/X86InstrInfo.cpp
@@ -561,6 +561,10 @@ X86InstrInfo::X86InstrInfo(X86TargetMachine &tm)
     { X86::VSQRTPSYr_Int,   X86::VSQRTPSYm_Int,       TB_ALIGN_32 },
     { X86::VBROADCASTSSYrr, X86::VBROADCASTSSYrm,     TB_NO_REVERSE },
     { X86::VBROADCASTSDYrr, X86::VBROADCASTSDYrm,     TB_NO_REVERSE },
+
+    // BMI/BMI2 foldable instructions
+    { X86::RORX32ri,        X86::RORX32mi,            0 },
+    { X86::RORX64ri,        X86::RORX64mi,            0 },
   };
 
   for (unsigned i = 0, e = array_lengthof(OpTbl1); i != e; ++i) {
diff --git a/llvm/lib/Target/X86/X86InstrShiftRotate.td b/llvm/lib/Target/X86/X86InstrShiftRotate.td
index bdeb63ffbd6..fe7d0ecf896 100644
--- a/llvm/lib/Target/X86/X86InstrShiftRotate.td
+++ b/llvm/lib/Target/X86/X86InstrShiftRotate.td
@@ -839,6 +839,16 @@ def SHRD64mri8 : RIi8<0xAC, MRMDestMem,
 
 } // Defs = [EFLAGS]
 
+def ROT32L2R_imm8  : SDNodeXForm<imm, [{
+  // Convert a ROTL shamt to a ROTR shamt on 32-bit integer.
+  return getI8Imm(32 - N->getZExtValue());
+}]>;
+
+def ROT64L2R_imm8  : SDNodeXForm<imm, [{
+  // Convert a ROTL shamt to a ROTR shamt on 64-bit integer.
+  return getI8Imm(64 - N->getZExtValue());
+}]>;
+
 multiclass bmi_rotate<string asm, RegisterClass RC, X86MemOperand x86memop> {
 let neverHasSideEffects = 1 in {
   def ri : Ii8<0xF0, MRMSrcReg, (outs RC:$dst), (ins RC:$src1, i8imm:$src2),
@@ -873,4 +883,17 @@ let Predicates = [HasBMI2] in {
   defm SHRX64 : bmi_shift<"shrx{q}", GR64, i64mem>, T8XD, VEX_W;
   defm SHLX32 : bmi_shift<"shlx{l}", GR32, i32mem>, T8, OpSize;
   defm SHLX64 : bmi_shift<"shlx{q}", GR64, i64mem>, T8, OpSize, VEX_W;
+
+  // Prefer RORX which is non-destructive and doesn't update EFLAGS.
+  let AddedComplexity = 10 in {
+    def : Pat<(rotl GR32:$src, (i8 imm:$shamt)),
+              (RORX32ri GR32:$src, (ROT32L2R_imm8 imm:$shamt))>;
+    def : Pat<(rotl GR64:$src, (i8 imm:$shamt)),
+              (RORX64ri GR64:$src, (ROT64L2R_imm8 imm:$shamt))>;
+  }
+
+  def : Pat<(rotl (loadi32 addr:$src), (i8 imm:$shamt)),
+            (RORX32mi addr:$src, (ROT32L2R_imm8 imm:$shamt))>;
+  def : Pat<(rotl (loadi64 addr:$src), (i8 imm:$shamt)),
+            (RORX64mi addr:$src, (ROT64L2R_imm8 imm:$shamt))>;
 }