Implement all llvm intrinsics necessary for the image crate

Fixes #1379

src/intrinsics/llvm_x86.rs

@@ -344,6 +344,109 @@ fn select4(
                 fx.bcx.ins().sshr(a_lane, saturated_count)
             });
         }
+        "llvm.x86.sse2.psad.bw" => {
+            intrinsic_args!(fx, args => (a, b); intrinsic);
+
+            assert_eq!(a.layout(), b.layout());
+            let layout = a.layout();
+
+            let (lane_count, lane_ty) = layout.ty.simd_size_and_type(fx.tcx);
+            let (ret_lane_count, ret_lane_ty) = ret.layout().ty.simd_size_and_type(fx.tcx);
+            assert_eq!(lane_ty, fx.tcx.types.u8);
+            assert_eq!(ret_lane_ty, fx.tcx.types.u64);
+            assert_eq!(lane_count, ret_lane_count * 8);
+
+            let ret_lane_layout = fx.layout_of(fx.tcx.types.u64);
+            for out_lane_idx in 0..lane_count / 8 {
+                let mut lane_diff_acc = fx.bcx.ins().iconst(types::I64, 0);
+
+                for lane_idx in out_lane_idx * 8..out_lane_idx * 8 + 1 {
+                    let a_lane = a.value_lane(fx, lane_idx).load_scalar(fx);
+                    let b_lane = b.value_lane(fx, lane_idx).load_scalar(fx);
+
+                    let lane_diff = fx.bcx.ins().isub(a_lane, b_lane);
+                    let abs_lane_diff = fx.bcx.ins().iabs(lane_diff);
+                    let abs_lane_diff = fx.bcx.ins().uextend(types::I64, abs_lane_diff);
+                    lane_diff_acc = fx.bcx.ins().iadd(lane_diff_acc, abs_lane_diff);
+                }
+
+                let res_lane = CValue::by_val(lane_diff_acc, ret_lane_layout);
+
+                ret.place_lane(fx, out_lane_idx).write_cvalue(fx, res_lane);
+            }
+        }
+        "llvm.x86.ssse3.pmadd.ub.sw.128" => {
+            intrinsic_args!(fx, args => (a, b); intrinsic);
+
+            let (lane_count, lane_ty) = a.layout().ty.simd_size_and_type(fx.tcx);
+            let (ret_lane_count, ret_lane_ty) = ret.layout().ty.simd_size_and_type(fx.tcx);
+            assert_eq!(lane_ty, fx.tcx.types.u8);
+            assert_eq!(ret_lane_ty, fx.tcx.types.i16);
+            assert_eq!(lane_count, ret_lane_count * 2);
+
+            let ret_lane_layout = fx.layout_of(fx.tcx.types.i16);
+            for out_lane_idx in 0..lane_count / 2 {
+                let a_lane0 = a.value_lane(fx, out_lane_idx * 2).load_scalar(fx);
+                let a_lane0 = fx.bcx.ins().uextend(types::I16, a_lane0);
+                let b_lane0 = b.value_lane(fx, out_lane_idx * 2).load_scalar(fx);
+                let b_lane0 = fx.bcx.ins().sextend(types::I16, b_lane0);
+
+                let a_lane1 = a.value_lane(fx, out_lane_idx * 2 + 1).load_scalar(fx);
+                let a_lane1 = fx.bcx.ins().uextend(types::I16, a_lane1);
+                let b_lane1 = b.value_lane(fx, out_lane_idx * 2 + 1).load_scalar(fx);
+                let b_lane1 = fx.bcx.ins().sextend(types::I16, b_lane1);
+
+                let mul0: Value = fx.bcx.ins().imul(a_lane0, b_lane0);
+                let mul1 = fx.bcx.ins().imul(a_lane1, b_lane1);
+
+                let (val, has_overflow) = fx.bcx.ins().sadd_overflow(mul0, mul1);
+
+                let rhs_ge_zero = fx.bcx.ins().icmp_imm(IntCC::SignedGreaterThanOrEqual, mul1, 0);
+
+                let min = fx.bcx.ins().iconst(types::I16, i64::from(i16::MIN as u16));
+                let max = fx.bcx.ins().iconst(types::I16, i64::from(i16::MAX as u16));
+
+                let sat_val = fx.bcx.ins().select(rhs_ge_zero, max, min);
+                let res_lane = fx.bcx.ins().select(has_overflow, sat_val, val);
+
+                let res_lane = CValue::by_val(res_lane, ret_lane_layout);
+
+                ret.place_lane(fx, out_lane_idx).write_cvalue(fx, res_lane);
+            }
+        }
+        "llvm.x86.sse2.pmadd.wd" => {
+            intrinsic_args!(fx, args => (a, b); intrinsic);
+
+            assert_eq!(a.layout(), b.layout());
+            let layout = a.layout();
+
+            let (lane_count, lane_ty) = layout.ty.simd_size_and_type(fx.tcx);
+            let (ret_lane_count, ret_lane_ty) = ret.layout().ty.simd_size_and_type(fx.tcx);
+            assert_eq!(lane_ty, fx.tcx.types.i16);
+            assert_eq!(ret_lane_ty, fx.tcx.types.i32);
+            assert_eq!(lane_count, ret_lane_count * 2);
+
+            let ret_lane_layout = fx.layout_of(fx.tcx.types.i32);
+            for out_lane_idx in 0..lane_count / 2 {
+                let a_lane0 = a.value_lane(fx, out_lane_idx * 2).load_scalar(fx);
+                let a_lane0 = fx.bcx.ins().uextend(types::I32, a_lane0);
+                let b_lane0 = b.value_lane(fx, out_lane_idx * 2).load_scalar(fx);
+                let b_lane0 = fx.bcx.ins().sextend(types::I32, b_lane0);
+
+                let a_lane1 = a.value_lane(fx, out_lane_idx * 2 + 1).load_scalar(fx);
+                let a_lane1 = fx.bcx.ins().uextend(types::I32, a_lane1);
+                let b_lane1 = b.value_lane(fx, out_lane_idx * 2 + 1).load_scalar(fx);
+                let b_lane1 = fx.bcx.ins().sextend(types::I32, b_lane1);
+
+                let mul0: Value = fx.bcx.ins().imul(a_lane0, b_lane0);
+                let mul1 = fx.bcx.ins().imul(a_lane1, b_lane1);
+
+                let res_lane = fx.bcx.ins().iadd(mul0, mul1);
+                let res_lane = CValue::by_val(res_lane, ret_lane_layout);
+
+                ret.place_lane(fx, out_lane_idx).write_cvalue(fx, res_lane);
+            }
+        }
         _ => {
             fx.tcx
                 .sess