[llvm] 95c2bcb - GlobalISel: Handle widening umulo/smulo condition outputs

[Matt Arsenault via llvm-commits]

Author: Matt Arsenault
Date: 2022-04-12T16:54:03-04:00
New Revision: 95c2bcbf8b98c176408e5cce82afef232b788b18

URL: https://github.com/llvm/llvm-project/commit/95c2bcbf8b98c176408e5cce82afef232b788b18
DIFF: https://github.com/llvm/llvm-project/commit/95c2bcbf8b98c176408e5cce82afef232b788b18.diff

LOG: GlobalISel: Handle widening umulo/smulo condition outputs

Added: 
    

Modified: 
    llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
    llvm/unittests/CodeGen/GlobalISel/LegalizerHelperTest.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
index 516cab8bda64a..deba716ee1d87 100644
--- a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
@@ -1988,8 +1988,12 @@ LegalizerHelper::widenScalarAddSubShlSat(MachineInstr &MI, unsigned TypeIdx,
 LegalizerHelper::LegalizeResult
 LegalizerHelper::widenScalarMulo(MachineInstr &MI, unsigned TypeIdx,
                                  LLT WideTy) {
-  if (TypeIdx == 1)
-    return UnableToLegalize;
+  if (TypeIdx == 1) {
+    Observer.changingInstr(MI);
+    widenScalarDst(MI, WideTy, 1);
+    Observer.changedInstr(MI);
+    return Legalized;
+  }
 
   bool IsSigned = MI.getOpcode() == TargetOpcode::G_SMULO;
   Register Result = MI.getOperand(0).getReg();

diff  --git a/llvm/unittests/CodeGen/GlobalISel/LegalizerHelperTest.cpp b/llvm/unittests/CodeGen/GlobalISel/LegalizerHelperTest.cpp
index 49d2c8329b30d..2a115c29ec0a4 100644
--- a/llvm/unittests/CodeGen/GlobalISel/LegalizerHelperTest.cpp
+++ b/llvm/unittests/CodeGen/GlobalISel/LegalizerHelperTest.cpp
@@ -1037,6 +1037,41 @@ TEST_F(AArch64GISelMITest, WidenSSUBE) {
   EXPECT_TRUE(CheckMachineFunction(*MF, CheckStr)) << *MF;
 }
 
+TEST_F(AArch64GISelMITest, WidenUMULOCondition) {
+  setUp();
+  if (!TM)
+    return;
+
+  // Declare your legalization info
+  DefineLegalizerInfo(A, {
+    getActionDefinitionsBuilder(G_ADD).legalFor({{s16, s16}});
+  });
+
+  LLT s32 = LLT::scalar(32);
+  LLT s64 = LLT::scalar(64);
+
+  auto UMulo =
+    B.buildInstr(TargetOpcode::G_UMULO, {s64, LLT::scalar(1)},
+                 {Copies[0], Copies[1]});
+  AInfo Info(MF->getSubtarget());
+  DummyGISelObserver Observer;
+  LegalizerHelper Helper(*MF, Info, Observer, B);
+
+  B.setInstrAndDebugLoc(*UMulo);
+  EXPECT_EQ(LegalizerHelper::LegalizeResult::Legalized,
+            Helper.widenScalar(*UMulo, 1, s32));
+
+  auto CheckStr = R"(
+  CHECK: [[COPY0:%[0-9]+]]:_(s64) = COPY
+  CHECK: [[COPY1:%[0-9]+]]:_(s64) = COPY
+  CHECK: [[ADD:%[0-9]+]]:_(s64), [[OVERFLOW:%[0-9]+]]:_(s32) = G_UMULO [[COPY0]]:_, [[COPY1]]:_
+  CHECK: {{[0-9]+}}:_(s1) = G_TRUNC [[OVERFLOW]]
+  )";
+
+  // Check
+  EXPECT_TRUE(CheckMachineFunction(*MF, CheckStr)) << *MF;
+}
+
 TEST_F(AArch64GISelMITest, NarrowUADDO) {
   setUp();
   if (!TM)