{ ISD::SRA, MVT::v32i8, 32*10 }, // Scalarized.
{ ISD::SRA, MVT::v16i16, 16*10 }, // Scalarized.
{ ISD::SRA, MVT::v4i64, 4*10 }, // Scalarized.
+
+ // Vectorizing division is a bad idea. See the SSE2 table for more comments.
+ { ISD::SDIV, MVT::v32i8, 32*20 },
+ { ISD::SDIV, MVT::v16i16, 16*20 },
+ { ISD::SDIV, MVT::v8i32, 8*20 },
+ { ISD::SDIV, MVT::v4i64, 4*20 },
+ { ISD::UDIV, MVT::v32i8, 32*20 },
+ { ISD::UDIV, MVT::v16i16, 16*20 },
+ { ISD::UDIV, MVT::v8i32, 8*20 },
+ { ISD::UDIV, MVT::v4i64, 4*20 },
};
// Look for AVX2 lowering tricks.
{ ISD::SRA, MVT::v8i16, 8*10 }, // Scalarized.
{ ISD::SRA, MVT::v4i32, 4*10 }, // Scalarized.
{ ISD::SRA, MVT::v2i64, 2*10 }, // Scalarized.
+
+ // It is not a good idea to vectorize division. We have to scalarize it and
+ // in the process we will often end up having to spilling regular
+ // registers. The overhead of division is going to dominate most kernels
+ // anyways so try hard to prevent vectorization of division - it is
+ // generally a bad idea. Assume somewhat arbitrarily that we have to be able
+ // to hide "20 cycles" for each lane.
+ { ISD::SDIV, MVT::v16i8, 16*20 },
+ { ISD::SDIV, MVT::v8i16, 8*20 },
+ { ISD::SDIV, MVT::v4i32, 4*20 },
+ { ISD::SDIV, MVT::v2i64, 2*20 },
+ { ISD::UDIV, MVT::v16i8, 16*20 },
+ { ISD::UDIV, MVT::v8i16, 8*20 },
+ { ISD::UDIV, MVT::v4i32, 4*20 },
+ { ISD::UDIV, MVT::v2i64, 2*20 },
};
if (ST->hasSSE2()) {
--- /dev/null
+; RUN: opt -mtriple=x86_64-apple-darwin -mcpu=core2 -cost-model -analyze < %s | FileCheck --check-prefix=SSE2 %s
+; RUN: opt -mtriple=x86_64-apple-darwin -mcpu=core-avx2 -cost-model -analyze < %s | FileCheck --check-prefix=AVX2 %s
+
+
+define void @div_sse() {
+ ; SSE2: div_sse
+ ; SSE2: cost of 320 {{.*}} sdiv
+ %a0 = sdiv <16 x i8> undef, undef
+ ; SSE2: cost of 160 {{.*}} sdiv
+ %a1 = sdiv <8 x i16> undef, undef
+ ; SSE2: cost of 80 {{.*}} sdiv
+ %a2 = sdiv <4 x i32> undef, undef
+ ; SSE2: cost of 40 {{.*}} sdiv
+ %a3 = sdiv <2 x i32> undef, undef
+ ret void
+}
+; SSE2: div_avx
+
+define void @div_avx() {
+ ; AVX2: div_avx
+ ; AVX2: cost of 640 {{.*}} sdiv
+ %a0 = sdiv <32 x i8> undef, undef
+ ; AVX2: cost of 320 {{.*}} sdiv
+ %a1 = sdiv <16 x i16> undef, undef
+ ; AVX2: cost of 160 {{.*}} sdiv
+ %a2 = sdiv <8 x i32> undef, undef
+ ; AVX2: cost of 80 {{.*}} sdiv
+ %a3 = sdiv <4 x i32> undef, undef
+ ret void
+}
+
+