[AVX512] Bring back vector-shuffle lowering support through broadcasts
Ffter commit at rev219046 512-bit broadcasts lowering become non-optimal. Most of tests on broadcasting and embedded broadcasting were changed and they doesn’t produce efficient code.
Example below is from commit changes (it’s the first test from test/CodeGen/X86/avx512-vbroadcast.ll):
define <16 x i32> @_inreg16xi32(i32 %a) {
; CHECK-LABEL: _inreg16xi32:
; CHECK: ## BB#0:
-; CHECK-NEXT: vpbroadcastd %edi, %zmm0
+; CHECK-NEXT: vmovd %edi, %xmm0
+; CHECK-NEXT: vpbroadcastd %xmm0, %ymm0
+; CHECK-NEXT: vinserti64x4 $1, %ymm0, %zmm0, %zmm0
; CHECK-NEXT: retq
%b = insertelement <16 x i32> undef, i32 %a, i32 0
%c = shufflevector <16 x i32> %b, <16 x i32> undef, <16 x i32> zeroinitializer
ret <16 x i32> %c
}
Here, 256-bit broadcast was generated instead of 512-bit one.
In this patch
1) I added vector-shuffle lowering through broadcasts
2) Removed asserts and branches likes because this is incorrect
- assert(Subtarget->hasDQI() && "We can only lower v8i64 with AVX-512-DQI");
3) Fixed lowering tests
llvm-svn: 220774
diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 16a21a9..656c1de 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -10231,7 +10231,6 @@
ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(Op);
ArrayRef<int> Mask = SVOp->getMask();
assert(Mask.size() == 8 && "Unexpected mask size for v8 shuffle!");
- assert(Subtarget->hasDQI() && "We can only lower v8i64 with AVX-512-DQI");
// FIXME: Implement direct support for this type!
return splitAndLowerVectorShuffle(DL, MVT::v8i64, V1, V2, Mask, DAG);
@@ -10247,7 +10246,6 @@
ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(Op);
ArrayRef<int> Mask = SVOp->getMask();
assert(Mask.size() == 16 && "Unexpected mask size for v16 shuffle!");
- assert(Subtarget->hasDQI() && "We can only lower v16i32 with AVX-512-DQI!");
// FIXME: Implement direct support for this type!
return splitAndLowerVectorShuffle(DL, MVT::v16i32, V1, V2, Mask, DAG);
@@ -10299,6 +10297,11 @@
assert(Subtarget->hasAVX512() &&
"Cannot lower 512-bit vectors w/ basic ISA!");
+ // Check for being able to broadcast a single element.
+ if (SDValue Broadcast = lowerVectorShuffleAsBroadcast(VT.SimpleTy, DL, V1,
+ Mask, Subtarget, DAG))
+ return Broadcast;
+
// Dispatch to each element type for lowering. If we don't have supprot for
// specific element type shuffles at 512 bits, immediately split them and
// lower them. Each lowering routine of a given type is allowed to assume that
@@ -10309,13 +10312,9 @@
case MVT::v16f32:
return lowerV16F32VectorShuffle(Op, V1, V2, Subtarget, DAG);
case MVT::v8i64:
- if (Subtarget->hasDQI())
- return lowerV8I64VectorShuffle(Op, V1, V2, Subtarget, DAG);
- break;
+ return lowerV8I64VectorShuffle(Op, V1, V2, Subtarget, DAG);
case MVT::v16i32:
- if (Subtarget->hasDQI())
- return lowerV16I32VectorShuffle(Op, V1, V2, Subtarget, DAG);
- break;
+ return lowerV16I32VectorShuffle(Op, V1, V2, Subtarget, DAG);
case MVT::v32i16:
if (Subtarget->hasBWI())
return lowerV32I16VectorShuffle(Op, V1, V2, Subtarget, DAG);
diff --git a/llvm/lib/Target/X86/X86InstrAVX512.td b/llvm/lib/Target/X86/X86InstrAVX512.td
index 1d1abcf..3dbc3d2 100644
--- a/llvm/lib/Target/X86/X86InstrAVX512.td
+++ b/llvm/lib/Target/X86/X86InstrAVX512.td
@@ -711,6 +711,16 @@
def : Pat<(v8f64 (X86VBroadcast (v2f64 VR128X:$src))),
(VBROADCASTSDZrr VR128X:$src)>;
+def : Pat<(v16f32 (X86VBroadcast (v16f32 VR512:$src))),
+ (VBROADCASTSSZrr (EXTRACT_SUBREG (v16f32 VR512:$src), sub_xmm))>;
+def : Pat<(v8f64 (X86VBroadcast (v8f64 VR512:$src))),
+ (VBROADCASTSDZrr (EXTRACT_SUBREG (v8f64 VR512:$src), sub_xmm))>;
+
+def : Pat<(v16i32 (X86VBroadcast (v16i32 VR512:$src))),
+ (VPBROADCASTDZrr (EXTRACT_SUBREG (v16i32 VR512:$src), sub_xmm))>;
+def : Pat<(v8i64 (X86VBroadcast (v8i64 VR512:$src))),
+ (VPBROADCASTQZrr (EXTRACT_SUBREG (v8i64 VR512:$src), sub_xmm))>;
+
def : Pat<(v16f32 (int_x86_avx512_vbroadcast_ss_ps_512 (v4f32 VR128X:$src))),
(VBROADCASTSSZrr VR128X:$src)>;
def : Pat<(v8f64 (int_x86_avx512_vbroadcast_sd_pd_512 (v2f64 VR128X:$src))),