[WebAssembly] Add more combine pattern for vector shift

After change with D144169, the codegen generates redundant instructions
like and and wrap. This fixes it.

Differential Revision: https://reviews.llvm.org/D144360

Author: junparser

llvm/lib/Target/WebAssembly/WebAssemblyInstrSIMD.td

@@ -971,6 +971,12 @@ def : Pat<(wasm_shr_s (v4i32 V128:$lhs), (and I32:$rhs, 31)),
 def : Pat<(wasm_shr_u (v4i32 V128:$lhs), (and I32:$rhs, 31)),
           (SHR_U_I32x4 V128:$lhs, I32:$rhs)>;
 
+def : Pat<(wasm_shl (v2i64 V128:$lhs), (and I32:$rhs, 63)),
+          (SHL_I64x2 V128:$lhs, I32:$rhs)>;
+def : Pat<(wasm_shr_s (v2i64 V128:$lhs), (and I32:$rhs, 63)),
+          (SHR_S_I64x2 V128:$lhs, I32:$rhs)>;
+def : Pat<(wasm_shr_u (v2i64 V128:$lhs), (and I32:$rhs, 63)),
+          (SHR_U_I64x2 V128:$lhs, I32:$rhs)>;
 def : Pat<(wasm_shl (v2i64 V128:$lhs), (trunc (and I64:$rhs, 63))),
           (SHL_I64x2 V128:$lhs, (I32_WRAP_I64 I64:$rhs))>;
 def : Pat<(wasm_shr_s (v2i64 V128:$lhs), (trunc (and I64:$rhs, 63))),

llvm/test/CodeGen/WebAssembly/masked-shifts.ll

@@ -502,3 +502,52 @@ define <2 x i64> @lshr_v2i64_late(<2 x i64> %v, i64 %x) {
   %a = lshr <2 x i64> %v, %m
   ret <2 x i64> %a
 }
+
+define <2 x i64> @shl_v2i64_i32(<2 x i64> %v, i32 %x) {
+; CHECK-LABEL: shl_v2i64_i32:
+; CHECK:         .functype shl_v2i64_i32 (v128, i32) -> (v128)
+; CHECK-NEXT:  # %bb.0:
+; CHECK-NEXT:    local.get 0
+; CHECK-NEXT:    local.get 1
+; CHECK-NEXT:    i64x2.shl
+; CHECK-NEXT:    # fallthrough-return
+  %z = and i32 %x, 63
+  %m = zext i32 %z to i64
+  %t = insertelement <2 x i64> undef, i64 %m, i32 0
+  %s = shufflevector <2 x i64> %t, <2 x i64> undef, <2 x i32> <i32 0, i32 0>
+  %a = shl <2 x i64> %v, %s
+  ret <2 x i64> %a
+}
+
+define <2 x i64> @ashr_v2i64_i32(<2 x i64> %v, i32 %x) {
+; CHECK-LABEL: ashr_v2i64_i32:
+; CHECK:         .functype ashr_v2i64_i32 (v128, i32) -> (v128)
+; CHECK-NEXT:  # %bb.0:
+; CHECK-NEXT:    local.get 0
+; CHECK-NEXT:    local.get 1
+; CHECK-NEXT:    i64x2.shr_s
+; CHECK-NEXT:    # fallthrough-return
+  %z = and i32 %x, 63
+  %m = zext i32 %z to i64
+  %t = insertelement <2 x i64> undef, i64 %m, i32 0
+  %s = shufflevector <2 x i64> %t, <2 x i64> undef, <2 x i32> <i32 0, i32 0>
+  %a = ashr <2 x i64> %v, %s
+  ret <2 x i64> %a
+}
+
+define <2 x i64> @lshr_v2i64_i32(<2 x i64> %v, i32 %x) {
+; CHECK-LABEL: lshr_v2i64_i32:
+; CHECK:         .functype lshr_v2i64_i32 (v128, i32) -> (v128)
+; CHECK-NEXT:  # %bb.0:
+; CHECK-NEXT:    local.get 0
+; CHECK-NEXT:    local.get 1
+; CHECK-NEXT:    i64x2.shr_u
+; CHECK-NEXT:    # fallthrough-return
+  %z = and i32 %x, 63
+  %m = zext i32 %z to i64
+  %t = insertelement <2 x i64> undef, i64 %m, i32 0
+  %s = shufflevector <2 x i64> %t, <2 x i64> undef, <2 x i32> <i32 0, i32 0>
+  %a = lshr <2 x i64> %v, %s
+  ret <2 x i64> %a
+}
+