[llvm] b6ad7ab - [RISCV] Prevent autovectorization using vscale with Zvl32b.
Craig Topper via llvm-commits
llvm-commits at lists.llvm.org
Wed Nov 2 13:55:40 PDT 2022
Author: Craig Topper
Date: 2022-11-02T13:55:21-07:00
New Revision: b6ad7ab89ef5e1772e90248ee728fd955089c949
URL: https://github.com/llvm/llvm-project/commit/b6ad7ab89ef5e1772e90248ee728fd955089c949
DIFF: https://github.com/llvm/llvm-project/commit/b6ad7ab89ef5e1772e90248ee728fd955089c949.diff
LOG: [RISCV] Prevent autovectorization using vscale with Zvl32b.
RVVBitsPerBlock is 64. If VLen==32, VLen/RVVBitsPerBlock is 0.
Reviewed By: reames
Differential Revision: https://reviews.llvm.org/D137280
Added:
llvm/test/Transforms/LoopVectorize/RISCV/zvl32b.ll
Modified:
clang/lib/Basic/Targets/RISCV.cpp
clang/test/CodeGen/riscv-vector-bits-vscale-range.c
llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp
Removed:
################################################################################
diff --git a/clang/lib/Basic/Targets/RISCV.cpp b/clang/lib/Basic/Targets/RISCV.cpp
index 36fa962749820..f6db5b8aaf45d 100644
--- a/clang/lib/Basic/Targets/RISCV.cpp
+++ b/clang/lib/Basic/Targets/RISCV.cpp
@@ -252,7 +252,8 @@ RISCVTargetInfo::getVScaleRange(const LangOptions &LangOpts) const {
return std::pair<unsigned, unsigned>(
LangOpts.VScaleMin ? LangOpts.VScaleMin : 1, LangOpts.VScaleMax);
- if (unsigned MinVLen = ISAInfo->getMinVLen()) {
+ if (unsigned MinVLen = ISAInfo->getMinVLen();
+ MinVLen >= llvm::RISCV::RVVBitsPerBlock) {
unsigned MaxVLen = ISAInfo->getMaxVLen();
// RISCV::RVVBitsPerBlock is 64.
return std::make_pair(MinVLen / llvm::RISCV::RVVBitsPerBlock,
diff --git a/clang/test/CodeGen/riscv-vector-bits-vscale-range.c b/clang/test/CodeGen/riscv-vector-bits-vscale-range.c
index 9fbb9795657b3..ed391f5d04e56 100644
--- a/clang/test/CodeGen/riscv-vector-bits-vscale-range.c
+++ b/clang/test/CodeGen/riscv-vector-bits-vscale-range.c
@@ -14,6 +14,7 @@
// RUN: %clang_cc1 -triple riscv64-none-linux-gnu -target-feature +zve64x -S -emit-llvm -o - %s | FileCheck %s --check-prefix=CHECK-ZVE64
// RUN: %clang_cc1 -triple riscv64-none-linux-gnu -target-feature +zve64f -target-feature +f -S -emit-llvm -o - %s | FileCheck %s --check-prefix=CHECK-ZVE64
// RUN: %clang_cc1 -triple riscv64-none-linux-gnu -target-feature +zve64d -target-feature +f -target-feature +d -S -emit-llvm -o - %s | FileCheck %s --check-prefix=CHECK-ZVE64
+// RUN: %clang_cc1 -triple riscv64-none-linux-gnu -target-feature +zve32x -S -emit-llvm -o - %s | FileCheck %s --check-prefix=CHECK-ZVE32
// CHECK-LABEL: @func() #0
// CHECK: attributes #0 = { {{.*}} vscale_range([[#VBITS]],[[#VBITS]]) {{.*}} }
@@ -22,4 +23,6 @@
// CHECK-V: attributes #0 = { {{.*}} vscale_range(2,1024) {{.*}} }
// CHECK-ZVL: attributes #0 = { {{.*}} vscale_range(8,1024) {{.*}} }
// CHECK-ZVE64: attributes #0 = { {{.*}} vscale_range(1,1024) {{.*}} }
+// CHECK-ZVE32: attributes #0
+// CHECK-ZVE32-NOT: vscale_range
void func(void) {}
diff --git a/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp b/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp
index d44f6a647caa3..afb21b868cecf 100644
--- a/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp
+++ b/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp
@@ -153,7 +153,9 @@ Optional<unsigned> RISCVTTIImpl::getMaxVScale() const {
Optional<unsigned> RISCVTTIImpl::getVScaleForTuning() const {
if (ST->hasVInstructions())
- return ST->getRealMinVLen() / RISCV::RVVBitsPerBlock;
+ if (unsigned MinVLen = ST->getRealMinVLen();
+ MinVLen >= RISCV::RVVBitsPerBlock)
+ return MinVLen / RISCV::RVVBitsPerBlock;
return BaseT::getVScaleForTuning();
}
@@ -169,7 +171,10 @@ RISCVTTIImpl::getRegisterBitWidth(TargetTransformInfo::RegisterKind K) const {
ST->useRVVForFixedLengthVectors() ? LMUL * ST->getRealMinVLen() : 0);
case TargetTransformInfo::RGK_ScalableVector:
return TypeSize::getScalable(
- ST->hasVInstructions() ? LMUL * RISCV::RVVBitsPerBlock : 0);
+ (ST->hasVInstructions() &&
+ ST->getRealMinVLen() >= RISCV::RVVBitsPerBlock)
+ ? LMUL * RISCV::RVVBitsPerBlock
+ : 0);
}
llvm_unreachable("Unsupported register kind");
diff --git a/llvm/test/Transforms/LoopVectorize/RISCV/zvl32b.ll b/llvm/test/Transforms/LoopVectorize/RISCV/zvl32b.ll
new file mode 100644
index 0000000000000..e4dd8479cdc5d
--- /dev/null
+++ b/llvm/test/Transforms/LoopVectorize/RISCV/zvl32b.ll
@@ -0,0 +1,69 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -loop-vectorize -scalable-vectorization=on -mtriple riscv64-linux-gnu -mattr=+zve32f,+f -S 2>%t | FileCheck %s
+
+target datalayout = "e-m:e-p:64:64-i64:64-i128:128-n64-S128"
+target triple = "riscv64"
+
+; We can't use scalable vectorization for Zvl32b due to RVVBitsPerBlock being
+; 64. Since our vscale value is vlen/RVVBitsPerBlock this makes vscale 0.
+; Make sure we fall back to fixed vectorization instead.
+define void @vector_add_i16(ptr noalias nocapture %a, i16 %v, i64 %n) {
+; CHECK-LABEL: @vector_add_i16(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: br i1 false, label [[SCALAR_PH:%.*]], label [[VECTOR_PH:%.*]]
+; CHECK: vector.ph:
+; CHECK-NEXT: [[BROADCAST_SPLATINSERT:%.*]] = insertelement <2 x i16> poison, i16 [[V:%.*]], i32 0
+; CHECK-NEXT: [[BROADCAST_SPLAT:%.*]] = shufflevector <2 x i16> [[BROADCAST_SPLATINSERT]], <2 x i16> poison, <2 x i32> zeroinitializer
+; CHECK-NEXT: [[BROADCAST_SPLATINSERT3:%.*]] = insertelement <2 x i16> poison, i16 [[V]], i32 0
+; CHECK-NEXT: [[BROADCAST_SPLAT4:%.*]] = shufflevector <2 x i16> [[BROADCAST_SPLATINSERT3]], <2 x i16> poison, <2 x i32> zeroinitializer
+; CHECK-NEXT: br label [[VECTOR_BODY:%.*]]
+; CHECK: vector.body:
+; CHECK-NEXT: [[INDEX:%.*]] = phi i64 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[VECTOR_BODY]] ]
+; CHECK-NEXT: [[VEC_IND:%.*]] = phi <2 x i64> [ <i64 0, i64 1>, [[VECTOR_PH]] ], [ [[VEC_IND_NEXT:%.*]], [[VECTOR_BODY]] ]
+; CHECK-NEXT: [[STEP_ADD:%.*]] = add <2 x i64> [[VEC_IND]], <i64 2, i64 2>
+; CHECK-NEXT: [[TMP0:%.*]] = getelementptr inbounds i32, ptr [[A:%.*]], <2 x i64> [[VEC_IND]]
+; CHECK-NEXT: [[TMP1:%.*]] = getelementptr inbounds i32, ptr [[A]], <2 x i64> [[STEP_ADD]]
+; CHECK-NEXT: [[WIDE_MASKED_GATHER:%.*]] = call <2 x i16> @llvm.masked.gather.v2i16.v2p0(<2 x ptr> [[TMP0]], i32 2, <2 x i1> <i1 true, i1 true>, <2 x i16> poison)
+; CHECK-NEXT: [[WIDE_MASKED_GATHER2:%.*]] = call <2 x i16> @llvm.masked.gather.v2i16.v2p0(<2 x ptr> [[TMP1]], i32 2, <2 x i1> <i1 true, i1 true>, <2 x i16> poison)
+; CHECK-NEXT: [[TMP2:%.*]] = add <2 x i16> [[WIDE_MASKED_GATHER]], [[BROADCAST_SPLAT]]
+; CHECK-NEXT: [[TMP3:%.*]] = add <2 x i16> [[WIDE_MASKED_GATHER2]], [[BROADCAST_SPLAT4]]
+; CHECK-NEXT: call void @llvm.masked.scatter.v2i16.v2p0(<2 x i16> [[TMP2]], <2 x ptr> [[TMP0]], i32 2, <2 x i1> <i1 true, i1 true>)
+; CHECK-NEXT: call void @llvm.masked.scatter.v2i16.v2p0(<2 x i16> [[TMP3]], <2 x ptr> [[TMP1]], i32 2, <2 x i1> <i1 true, i1 true>)
+; CHECK-NEXT: [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 4
+; CHECK-NEXT: [[VEC_IND_NEXT]] = add <2 x i64> [[STEP_ADD]], <i64 2, i64 2>
+; CHECK-NEXT: [[TMP4:%.*]] = icmp eq i64 [[INDEX_NEXT]], 1024
+; CHECK-NEXT: br i1 [[TMP4]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP0:![0-9]+]]
+; CHECK: middle.block:
+; CHECK-NEXT: [[CMP_N:%.*]] = icmp eq i64 1024, 1024
+; CHECK-NEXT: br i1 [[CMP_N]], label [[FOR_END:%.*]], label [[SCALAR_PH]]
+; CHECK: scalar.ph:
+; CHECK-NEXT: [[BC_RESUME_VAL:%.*]] = phi i64 [ 1024, [[MIDDLE_BLOCK]] ], [ 0, [[ENTRY:%.*]] ]
+; CHECK-NEXT: br label [[FOR_BODY:%.*]]
+; CHECK: for.body:
+; CHECK-NEXT: [[IV:%.*]] = phi i64 [ [[BC_RESUME_VAL]], [[SCALAR_PH]] ], [ [[IV_NEXT:%.*]], [[FOR_BODY]] ]
+; CHECK-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds i32, ptr [[A]], i64 [[IV]]
+; CHECK-NEXT: [[ELEM:%.*]] = load i16, ptr [[ARRAYIDX]], align 2
+; CHECK-NEXT: [[ADD:%.*]] = add i16 [[ELEM]], [[V]]
+; CHECK-NEXT: store i16 [[ADD]], ptr [[ARRAYIDX]], align 2
+; CHECK-NEXT: [[IV_NEXT]] = add nuw nsw i64 [[IV]], 1
+; CHECK-NEXT: [[EXITCOND_NOT:%.*]] = icmp eq i64 [[IV_NEXT]], 1024
+; CHECK-NEXT: br i1 [[EXITCOND_NOT]], label [[FOR_END]], label [[FOR_BODY]], !llvm.loop [[LOOP2:![0-9]+]]
+; CHECK: for.end:
+; CHECK-NEXT: ret void
+;
+entry:
+ br label %for.body
+
+for.body:
+ %iv = phi i64 [ 0, %entry ], [ %iv.next, %for.body ]
+ %arrayidx = getelementptr inbounds i32, ptr %a, i64 %iv
+ %elem = load i16, ptr %arrayidx
+ %add = add i16 %elem, %v
+ store i16 %add, ptr %arrayidx
+ %iv.next = add nuw nsw i64 %iv, 1
+ %exitcond.not = icmp eq i64 %iv.next, 1024
+ br i1 %exitcond.not, label %for.end, label %for.body
+
+for.end:
+ ret void
+}
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