From: Matt Arsenault <matt@MattBook.local>
Date: Thu, 18 May 2023 08:42:54 +0000 (+0100)
Subject: Revert "ValueTracking: Handle phi in computeKnownFPClass"
X-Git-Tag: upstream/17.0.6~8033
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=e13f88d1ff5234946af6349a9a7cf56fcb6c040e;p=platform%2Fupstream%2Fllvm.git

Revert "ValueTracking: Handle phi in computeKnownFPClass"

This reverts commit cac9e427eb1ff3dabda8ac08968b998c3bc5ab47.

Causing crashes in lencod
---

diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index 906ae81..3b70029 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -5094,47 +5094,6 @@ void computeKnownFPClass(const Value *V, const APInt &DemandedElts,
                         Known, Depth + 1, Q, TLI);
     break;
   }
-  case Instruction::PHI: {
-    const PHINode *P = cast<PHINode>(Op);
-    // Unreachable blocks may have zero-operand PHI nodes.
-    if (P->getNumIncomingValues() == 0)
-      break;
-
-    // Otherwise take the unions of the known bit sets of the operands,
-    // taking conservative care to avoid excessive recursion.
-    if (Depth < MaxAnalysisRecursionDepth - 1) {
-      // Skip if every incoming value references to ourself.
-      if (isa_and_nonnull<UndefValue>(P->hasConstantValue()))
-        break;
-
-      bool First = true;
-
-      for (Value *IncValue : P->incoming_values()) {
-        // Skip direct self references.
-        if (IncValue == P)
-          continue;
-
-        KnownFPClass KnownSrc;
-        // Recurse, but cap the recursion to two levels, because we don't want
-        // to waste time spinning around in loops. We need at least depth 2 to
-        // detect known sign bits.
-        computeKnownFPClass(IncValue, DemandedElts, InterestedClasses, KnownSrc,
-                            MaxAnalysisRecursionDepth - 2, Q, TLI);
-
-        if (First) {
-          Known = KnownSrc;
-          First = false;
-        } else {
-          Known |= KnownSrc;
-        }
-
-        if (Known.KnownFPClasses == fcAllFlags)
-          break;
-      }
-    }
-
-    break;
-  }
   default:
     break;
   }
diff --git a/llvm/unittests/Analysis/ValueTrackingTest.cpp b/llvm/unittests/Analysis/ValueTrackingTest.cpp
index 3684f6f..c83fb62 100644
--- a/llvm/unittests/Analysis/ValueTrackingTest.cpp
+++ b/llvm/unittests/Analysis/ValueTrackingTest.cpp
@@ -1630,114 +1630,6 @@ TEST_F(ComputeKnownFPClassTest, FMulNoZero) {
   expectKnownFPClass(fcAllFlags, std::nullopt, A7);
 }
 
-TEST_F(ComputeKnownFPClassTest, Phi) {
-  parseAssembly(
-      "define float @test(i1 %cond, float nofpclass(nan inf) %arg0, float nofpclass(nan) %arg1) {\n"
-      "entry:\n"
-      "  br i1 %cond, label %bb0, label %bb1\n"
-      "bb0:\n"
-      "  br label %ret\n"
-      "bb1:\n"
-      "  br label %ret\n"
-      "ret:\n"
-      "  %A = phi float [ %arg0, %bb0 ],  [ %arg1, %bb1 ]\n"
-      "  ret float %A\n"
-      "}\n");
-  expectKnownFPClass(~fcNan, std::nullopt);
-}
-
-TEST_F(ComputeKnownFPClassTest, PhiKnownSignFalse) {
-  parseAssembly(
-      "declare float @llvm.fabs.f32(float)"
-      "define float @test(i1 %cond, float nofpclass(nan) %arg0, float nofpclass(nan) %arg1) {\n"
-      "entry:\n"
-      "  br i1 %cond, label %bb0, label %bb1\n"
-      "bb0:\n"
-      "  %fabs.arg0 = call float @llvm.fabs.f32(float %arg0)\n"
-      "  br label %ret\n"
-      "bb1:\n"
-      "  %fabs.arg1 = call float @llvm.fabs.f32(float %arg1)\n"
-      "  br label %ret\n"
-      "ret:\n"
-      "  %A = phi float [ %fabs.arg0, %bb0 ],  [ %fabs.arg1, %bb1 ]\n"
-      "  ret float %A\n"
-      "}\n");
-  expectKnownFPClass(fcPositive, false);
-}
-
-TEST_F(ComputeKnownFPClassTest, PhiKnownSignTrue) {
-  parseAssembly(
-      "declare float @llvm.fabs.f32(float)"
-      "define float @test(i1 %cond, float nofpclass(nan) %arg0, float %arg1) {\n"
-      "entry:\n"
-      "  br i1 %cond, label %bb0, label %bb1\n"
-      "bb0:\n"
-      "  %fabs.arg0 = call float @llvm.fabs.f32(float %arg0)\n"
-      "  %fneg.fabs.arg0 = fneg float %fabs.arg0\n"
-      "  br label %ret\n"
-      "bb1:\n"
-      "  %fabs.arg1 = call float @llvm.fabs.f32(float %arg1)\n"
-      "  %fneg.fabs.arg1 = fneg float %fabs.arg1\n"
-      "  br label %ret\n"
-      "ret:\n"
-      "  %A = phi float [ %fneg.fabs.arg0, %bb0 ],  [ %fneg.fabs.arg1, %bb1 ]\n"
-      "  ret float %A\n"
-      "}\n");
-  expectKnownFPClass(fcNegative | fcNan, true);
-}
-
-TEST_F(ComputeKnownFPClassTest, UnreachablePhi) {
-  parseAssembly(
-      "define float @test(float %arg) {\n"
-      "entry:\n"
-      "  ret float 0.0\n"
-      "unreachable:\n"
-      "  %A = phi float\n"
-      "  ret float %A\n"
-      "}\n");
-  expectKnownFPClass(fcAllFlags, std::nullopt);
-}
-
-TEST_F(ComputeKnownFPClassTest, SelfPhiOnly) {
-  parseAssembly(
-      "define float @test(float %arg) {\n"
-      "entry:\n"
-      "  ret float 0.0\n"
-      "loop:\n"
-      "  %A = phi float [ %A, %loop ]\n"
-      "  br label %loop\n"
-      "}\n");
-  expectKnownFPClass(fcAllFlags, std::nullopt);
-}
-
-TEST_F(ComputeKnownFPClassTest, SelfPhiFirstArg) {
-  parseAssembly(
-      "define float @test(i1 %cond, float nofpclass(inf) %arg) {\n"
-      "entry:\n"
-      "  br i1 %cond, label %loop, label %ret\n"
-      "loop:\n"
-      "  %A = phi float [ %arg, %entry ], [ %A, %loop ]\n"
-      "  br label %loop\n"
-      "ret:\n"
-      "  ret float %A"
-      "}\n");
-  expectKnownFPClass(~fcInf, std::nullopt);
-}
-
-TEST_F(ComputeKnownFPClassTest, SelfPhiSecondArg) {
-  parseAssembly(
-      "define float @test(i1 %cond, float nofpclass(inf) %arg) {\n"
-      "entry:\n"
-      "  br i1 %cond, label %loop, label %ret\n"
-      "loop:\n"
-      "  %A = phi float [ %A, %loop ], [ %arg, %entry ]\n"
-      "  br label %loop\n"
-      "ret:\n"
-      "  ret float %A"
-      "}\n");
-  expectKnownFPClass(~fcInf, std::nullopt);
-}
-
 TEST_F(ComputeKnownFPClassTest, CannotBeOrderedLessThanZero) {
   parseAssembly("define float @test(float %arg) {\n"
                 "  %A = fmul float %arg, %arg"