[WebAssembly] Implement the rotate instructions.

llvm-svn: 264076

2 files changed, 9 insertions, 1 deletions

diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
index e3600b4bf6f..159c4ac2e3a 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
@@ -95,7 +95,7 @@ WebAssemblyTargetLowering::WebAssemblyTargetLowering(
   for (auto T : {MVT::i32, MVT::i64}) {
     // Expand unavailable integer operations.
     for (auto Op :
-         {ISD::BSWAP, ISD::ROTL, ISD::ROTR, ISD::SMUL_LOHI, ISD::UMUL_LOHI,
+         {ISD::BSWAP, ISD::SMUL_LOHI, ISD::UMUL_LOHI,
           ISD::MULHS, ISD::MULHU, ISD::SDIVREM, ISD::UDIVREM, ISD::SHL_PARTS,
           ISD::SRA_PARTS, ISD::SRL_PARTS, ISD::ADDC, ISD::ADDE, ISD::SUBC,
           ISD::SUBE}) {
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyInstrInteger.td b/llvm/lib/Target/WebAssembly/WebAssemblyInstrInteger.td
index f5404ec8c8a..a597ac950a8 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyInstrInteger.td
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyInstrInteger.td
@@ -36,6 +36,8 @@ defm XOR : BinaryInt<xor, "xor ">;
 defm SHL : BinaryInt<shl, "shl ">;
 defm SHR_U : BinaryInt<srl, "shr_u">;
 defm SHR_S : BinaryInt<sra, "shr_s">;
+defm ROTL : BinaryInt<rotl, "rotl">;
+defm ROTR : BinaryInt<rotr, "rotr">;
 
 let isCommutable = 1 in {
 defm EQ : ComparisonInt<SETEQ, "eq  ">;
@@ -69,6 +71,12 @@ def : Pat<(ctlz_zero_undef I64:$src), (CLZ_I64 I64:$src)>;
 def : Pat<(cttz_zero_undef I32:$src), (CTZ_I32 I32:$src)>;
 def : Pat<(cttz_zero_undef I64:$src), (CTZ_I64 I64:$src)>;
 
+// Optimize away an explicit mask on a rotate count.
+def : Pat<(rotl I32:$lhs, (and I32:$rhs, 31)), (ROTL_I32 I32:$lhs, I32:$rhs)>;
+def : Pat<(rotr I32:$lhs, (and I32:$rhs, 31)), (ROTR_I32 I32:$lhs, I32:$rhs)>;
+def : Pat<(rotl I64:$lhs, (and I64:$rhs, 63)), (ROTL_I64 I64:$lhs, I64:$rhs)>;
+def : Pat<(rotr I64:$lhs, (and I64:$rhs, 63)), (ROTR_I64 I64:$lhs, I64:$rhs)>;
+
 let Defs = [ARGUMENTS] in {
 
 def SELECT_I32 : I<(outs I32:$dst), (ins I32:$lhs, I32:$rhs, I32:$cond),