4 files changed, 117 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),
diff --git a/llvm/test/CodeGen/WebAssembly/i32.ll b/llvm/test/CodeGen/WebAssembly/i32.ll
index d241b80ed3f..945a4470ed0 100644
--- a/llvm/test/CodeGen/WebAssembly/i32.ll
+++ b/llvm/test/CodeGen/WebAssembly/i32.ll
@@ -199,3 +199,57 @@ define i32 @eqz32(i32 %x) {
   %b = zext i1 %a to i32
   ret i32 %b
 }
+
+; CHECK-LABEL: rotl:
+; CHECK-NEXT: .param i32, i32{{$}}
+; CHECK-NEXT: .result i32{{$}}
+; CHECK-NEXT: i32.rotl $push0=, $0, $1
+; CHECK-NEXT: return $pop0{{$}}
+define i32 @rotl(i32 %x, i32 %y) {
+  %z = sub i32 32, %y
+  %b = shl i32 %x, %y
+  %c = lshr i32 %x, %z
+  %d = or i32 %b, %c
+  ret i32 %d
+}
+
+; CHECK-LABEL: masked_rotl:
+; CHECK-NEXT: .param i32, i32{{$}}
+; CHECK-NEXT: .result i32{{$}}
+; CHECK-NEXT: i32.rotl $push0=, $0, $1
+; CHECK-NEXT: return $pop0{{$}}
+define i32 @masked_rotl(i32 %x, i32 %y) {
+  %a = and i32 %y, 31
+  %z = sub i32 32, %a
+  %b = shl i32 %x, %a
+  %c = lshr i32 %x, %z
+  %d = or i32 %b, %c
+  ret i32 %d
+}
+
+; CHECK-LABEL: rotr:
+; CHECK-NEXT: .param i32, i32{{$}}
+; CHECK-NEXT: .result i32{{$}}
+; CHECK-NEXT: i32.rotr $push0=, $0, $1
+; CHECK-NEXT: return $pop0{{$}}
+define i32 @rotr(i32 %x, i32 %y) {
+  %z = sub i32 32, %y
+  %b = lshr i32 %x, %y
+  %c = shl i32 %x, %z
+  %d = or i32 %b, %c
+  ret i32 %d
+}
+
+; CHECK-LABEL: masked_rotr:
+; CHECK-NEXT: .param i32, i32{{$}}
+; CHECK-NEXT: .result i32{{$}}
+; CHECK-NEXT: i32.rotr $push0=, $0, $1
+; CHECK-NEXT: return $pop0{{$}}
+define i32 @masked_rotr(i32 %x, i32 %y) {
+  %a = and i32 %y, 31
+  %z = sub i32 32, %a
+  %b = lshr i32 %x, %a
+  %c = shl i32 %x, %z
+  %d = or i32 %b, %c
+  ret i32 %d
+}
diff --git a/llvm/test/CodeGen/WebAssembly/i64.ll b/llvm/test/CodeGen/WebAssembly/i64.ll
index c2a1bb6b970..85a8ae34dcb 100644
--- a/llvm/test/CodeGen/WebAssembly/i64.ll
+++ b/llvm/test/CodeGen/WebAssembly/i64.ll
@@ -199,3 +199,57 @@ define i32 @eqz64(i64 %x) {
   %b = zext i1 %a to i32
   ret i32 %b
 }
+
+; CHECK-LABEL: rotl:
+; CHECK-NEXT: .param i64, i64{{$}}
+; CHECK-NEXT: .result i64{{$}}
+; CHECK-NEXT: i64.rotl $push0=, $0, $1
+; CHECK-NEXT: return $pop0{{$}}
+define i64 @rotl(i64 %x, i64 %y) {
+  %z = sub i64 64, %y
+  %b = shl i64 %x, %y
+  %c = lshr i64 %x, %z
+  %d = or i64 %b, %c
+  ret i64 %d
+}
+
+; CHECK-LABEL: masked_rotl:
+; CHECK-NEXT: .param i64, i64{{$}}
+; CHECK-NEXT: .result i64{{$}}
+; CHECK-NEXT: i64.rotl $push0=, $0, $1
+; CHECK-NEXT: return $pop0{{$}}
+define i64 @masked_rotl(i64 %x, i64 %y) {
+  %a = and i64 %y, 63
+  %z = sub i64 64, %a
+  %b = shl i64 %x, %a
+  %c = lshr i64 %x, %z
+  %d = or i64 %b, %c
+  ret i64 %d
+}
+
+; CHECK-LABEL: rotr:
+; CHECK-NEXT: .param i64, i64{{$}}
+; CHECK-NEXT: .result i64{{$}}
+; CHECK-NEXT: i64.rotr $push0=, $0, $1
+; CHECK-NEXT: return $pop0{{$}}
+define i64 @rotr(i64 %x, i64 %y) {
+  %z = sub i64 64, %y
+  %b = lshr i64 %x, %y
+  %c = shl i64 %x, %z
+  %d = or i64 %b, %c
+  ret i64 %d
+}
+
+; CHECK-LABEL: masked_rotr:
+; CHECK-NEXT: .param i64, i64{{$}}
+; CHECK-NEXT: .result i64{{$}}
+; CHECK-NEXT: i64.rotr $push0=, $0, $1
+; CHECK-NEXT: return $pop0{{$}}
+define i64 @masked_rotr(i64 %x, i64 %y) {
+  %a = and i64 %y, 63
+  %z = sub i64 64, %a
+  %b = lshr i64 %x, %a
+  %c = shl i64 %x, %z
+  %d = or i64 %b, %c
+  ret i64 %d
+}