[llvm] b396921 - [SCCP] Handle llvm.vscale intrinsic calls (#114033)
via llvm-commits
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Thu Oct 31 05:22:19 PDT 2024
Author: Hari Limaye
Date: 2024-10-31T12:22:15Z
New Revision: b396921d0c7d9ad396a1ee6ac85d0dbda965699f
URL: https://github.com/llvm/llvm-project/commit/b396921d0c7d9ad396a1ee6ac85d0dbda965699f
DIFF: https://github.com/llvm/llvm-project/commit/b396921d0c7d9ad396a1ee6ac85d0dbda965699f.diff
LOG: [SCCP] Handle llvm.vscale intrinsic calls (#114033)
Teach SCCP to compute a constant range for calls to llvm.vscale
intrinsics.
Added:
llvm/test/Transforms/SCCP/vscale-intrinsic.ll
Modified:
llvm/lib/Transforms/Utils/SCCPSolver.cpp
Removed:
################################################################################
diff --git a/llvm/lib/Transforms/Utils/SCCPSolver.cpp b/llvm/lib/Transforms/Utils/SCCPSolver.cpp
index c65710ea7551ac..4225e7e80fda6f 100644
--- a/llvm/lib/Transforms/Utils/SCCPSolver.cpp
+++ b/llvm/lib/Transforms/Utils/SCCPSolver.cpp
@@ -1923,6 +1923,12 @@ void SCCPInstVisitor::handleCallResult(CallBase &CB) {
return (void)mergeInValue(IV, &CB, CopyOfVal);
}
+ if (II->getIntrinsicID() == Intrinsic::vscale) {
+ unsigned BitWidth = CB.getType()->getScalarSizeInBits();
+ const ConstantRange Result = getVScaleRange(II->getFunction(), BitWidth);
+ return (void)mergeInValue(II, ValueLatticeElement::getRange(Result));
+ }
+
if (ConstantRange::isIntrinsicSupported(II->getIntrinsicID())) {
// Compute result range for intrinsics supported by ConstantRange.
// Do this even if we don't know a range for all operands, as we may
diff --git a/llvm/test/Transforms/SCCP/vscale-intrinsic.ll b/llvm/test/Transforms/SCCP/vscale-intrinsic.ll
new file mode 100644
index 00000000000000..7dc7ea9b991912
--- /dev/null
+++ b/llvm/test/Transforms/SCCP/vscale-intrinsic.ll
@@ -0,0 +1,81 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt < %s -passes=sccp -S | FileCheck %s
+
+define i1 @vscale_i32_noattr() {
+; CHECK-LABEL: define i1 @vscale_i32_noattr() {
+; CHECK-NEXT: [[SCALE:%.*]] = call i32 @llvm.vscale.i32()
+; CHECK-NEXT: [[CMP2:%.*]] = icmp ule i32 [[SCALE]], 16
+; CHECK-NEXT: [[RES:%.*]] = and i1 true, [[CMP2]]
+; CHECK-NEXT: ret i1 [[RES]]
+;
+ %scale = call i32 @llvm.vscale.i32()
+ %cmp1 = icmp uge i32 %scale, 1
+ %cmp2 = icmp ule i32 %scale, 16
+ %res = and i1 %cmp1, %cmp2
+ ret i1 %res
+}
+
+define i1 @vscale_i32_attr() vscale_range(1, 16) {
+; CHECK-LABEL: define i1 @vscale_i32_attr(
+; CHECK-SAME: ) #[[ATTR0:[0-9]+]] {
+; CHECK-NEXT: [[SCALE:%.*]] = call i32 @llvm.vscale.i32()
+; CHECK-NEXT: ret i1 true
+;
+ %scale = call i32 @llvm.vscale.i32()
+ %cmp1 = icmp uge i32 %scale, 1
+ %cmp2 = icmp ule i32 %scale, 16
+ %res = and i1 %cmp1, %cmp2
+ ret i1 %res
+}
+
+define i1 @vscale_i64_noattr() {
+; CHECK-LABEL: define i1 @vscale_i64_noattr() {
+; CHECK-NEXT: [[SCALE:%.*]] = call i64 @llvm.vscale.i64()
+; CHECK-NEXT: [[CMP2:%.*]] = icmp ule i64 [[SCALE]], 16
+; CHECK-NEXT: [[RES:%.*]] = and i1 true, [[CMP2]]
+; CHECK-NEXT: ret i1 [[RES]]
+;
+ %scale = call i64 @llvm.vscale.i64()
+ %cmp1 = icmp uge i64 %scale, 1
+ %cmp2 = icmp ule i64 %scale, 16
+ %res = and i1 %cmp1, %cmp2
+ ret i1 %res
+}
+
+define i1 @vscale_i64_attr() vscale_range(1, 16) {
+; CHECK-LABEL: define i1 @vscale_i64_attr(
+; CHECK-SAME: ) #[[ATTR0]] {
+; CHECK-NEXT: [[SCALE:%.*]] = call i64 @llvm.vscale.i64()
+; CHECK-NEXT: ret i1 true
+;
+ %scale = call i64 @llvm.vscale.i64()
+ %cmp1 = icmp uge i64 %scale, 1
+ %cmp2 = icmp ule i64 %scale, 16
+ %res = and i1 %cmp1, %cmp2
+ ret i1 %res
+}
+
+define i32 @vscale_branch_elim(i32 %x) vscale_range(1, 16) {
+; CHECK-LABEL: define i32 @vscale_branch_elim(
+; CHECK-SAME: i32 [[X:%.*]]) #[[ATTR0]] {
+; CHECK-NEXT: [[ENTRY:.*:]]
+; CHECK-NEXT: [[SCALE:%.*]] = call i32 @llvm.vscale.i32()
+; CHECK-NEXT: [[BOUND:%.*]] = shl nuw nsw i32 [[SCALE]], 3
+; CHECK-NEXT: br label %[[IF_END:.*]]
+; CHECK: [[IF_END]]:
+; CHECK-NEXT: ret i32 [[X]]
+;
+entry:
+ %scale = call i32 @llvm.vscale.i32()
+ %bound = shl nsw nuw i32 %scale, 3
+ %cmp = icmp uge i32 1, %bound
+ br i1 %cmp, label %if.then, label %if.end
+
+if.then:
+ %double = mul i32 %x, 2
+ br label %if.end
+
+if.end:
+ %res = phi i32 [ %x, %entry ], [ %double, %if.then]
+ ret i32 %res
+}
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