[PATCH] D87183: [SCCP] Compute ranges for supported intrinsics

[Nikita Popov via Phabricator via llvm-commits]

This revision was automatically updated to reflect the committed changes.
Closed by commit rG9fb46a452d4e: [SCCP] Compute ranges for supported intrinsics (authored by nikic).

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D87183/new/

https://reviews.llvm.org/D87183

Files:
  llvm/lib/Transforms/Scalar/SCCP.cpp
  llvm/test/Transforms/SCCP/intrinsics.ll


Index: llvm/test/Transforms/SCCP/intrinsics.ll
===================================================================
--- llvm/test/Transforms/SCCP/intrinsics.ll
+++ llvm/test/Transforms/SCCP/intrinsics.ll
@@ -12,10 +12,8 @@
 ; CHECK-LABEL: @abs1(
 ; CHECK-NEXT:    [[X:%.*]] = load i8, i8* [[P:%.*]], align 1, [[RNG0:!range !.*]]
 ; CHECK-NEXT:    [[ABS:%.*]] = call i8 @llvm.abs.i8(i8 [[X]], i1 false)
-; CHECK-NEXT:    [[CMP1:%.*]] = icmp sge i8 [[ABS]], 0
-; CHECK-NEXT:    call void @use(i1 [[CMP1]])
-; CHECK-NEXT:    [[CMP2:%.*]] = icmp slt i8 [[ABS]], 10
-; CHECK-NEXT:    call void @use(i1 [[CMP2]])
+; CHECK-NEXT:    call void @use(i1 true)
+; CHECK-NEXT:    call void @use(i1 true)
 ; CHECK-NEXT:    [[CMP3:%.*]] = icmp sge i8 [[ABS]], 1
 ; CHECK-NEXT:    call void @use(i1 [[CMP3]])
 ; CHECK-NEXT:    [[CMP4:%.*]] = icmp slt i8 [[ABS]], 9
@@ -40,8 +38,7 @@
 define void @abs2(i8 %x) {
 ; CHECK-LABEL: @abs2(
 ; CHECK-NEXT:    [[ABS:%.*]] = call i8 @llvm.abs.i8(i8 [[X:%.*]], i1 true)
-; CHECK-NEXT:    [[CMP:%.*]] = icmp sge i8 [[ABS]], 0
-; CHECK-NEXT:    call void @use(i1 [[CMP]])
+; CHECK-NEXT:    call void @use(i1 true)
 ; CHECK-NEXT:    ret void
 ;
   %abs = call i8 @llvm.abs.i8(i8 %x, i1 true)
@@ -68,10 +65,8 @@
 ; CHECK-NEXT:    [[X1:%.*]] = load i8, i8* [[P1:%.*]], align 1, [[RNG1:!range !.*]]
 ; CHECK-NEXT:    [[X2:%.*]] = load i8, i8* [[P2:%.*]], align 1, [[RNG2:!range !.*]]
 ; CHECK-NEXT:    [[M:%.*]] = call i8 @llvm.umax.i8(i8 [[X1]], i8 [[X2]])
-; CHECK-NEXT:    [[CMP1:%.*]] = icmp uge i8 [[M]], 5
-; CHECK-NEXT:    call void @use(i1 [[CMP1]])
-; CHECK-NEXT:    [[CMP2:%.*]] = icmp ult i8 [[M]], 15
-; CHECK-NEXT:    call void @use(i1 [[CMP2]])
+; CHECK-NEXT:    call void @use(i1 true)
+; CHECK-NEXT:    call void @use(i1 true)
 ; CHECK-NEXT:    [[CMP3:%.*]] = icmp uge i8 [[M]], 6
 ; CHECK-NEXT:    call void @use(i1 [[CMP3]])
 ; CHECK-NEXT:    [[CMP4:%.*]] = icmp ult i8 [[M]], 14
@@ -95,8 +90,7 @@
 define void @umax2(i8 %x) {
 ; CHECK-LABEL: @umax2(
 ; CHECK-NEXT:    [[M:%.*]] = call i8 @llvm.umax.i8(i8 [[X:%.*]], i8 10)
-; CHECK-NEXT:    [[CMP:%.*]] = icmp uge i8 [[M]], 10
-; CHECK-NEXT:    call void @use(i1 [[CMP]])
+; CHECK-NEXT:    call void @use(i1 true)
 ; CHECK-NEXT:    ret void
 ;
   %m = call i8 @llvm.umax.i8(i8 %x, i8 10)
Index: llvm/lib/Transforms/Scalar/SCCP.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/SCCP.cpp
+++ llvm/lib/Transforms/Scalar/SCCP.cpp
@@ -1350,6 +1350,25 @@
 
       return (void)mergeInValue(IV, &CB, CopyOfVal);
     }
+
+    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
+      // still know something about the result range, e.g. of abs(x).
+      SmallVector<ConstantRange, 2> OpRanges;
+      for (Value *Op : II->args()) {
+        const ValueLatticeElement &State = getValueState(Op);
+        if (State.isConstantRange())
+          OpRanges.push_back(State.getConstantRange());
+        else
+          OpRanges.push_back(
+              ConstantRange::getFull(Op->getType()->getScalarSizeInBits()));
+      }
+
+      ConstantRange Result =
+          ConstantRange::intrinsic(II->getIntrinsicID(), OpRanges);
+      return (void)mergeInValue(II, ValueLatticeElement::getRange(Result));
+    }
   }
 
   // The common case is that we aren't tracking the callee, either because we


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