GlobalISel: Fix CSE handling of buildConstant

This fixes two problems with CSE done in buildConstant. First, this
would hit an assert when used with a vector result type. Solve this by
allowing CSE on the vector elements, but not on the result vector for
now.

Second, this was also performing the CSE based on the input
ConstantInt pointer. The underlying buildConstant could potentially
convert the constant depending on the result type, giving in a
different ConstantInt*. Stop allowing the APInt and ConstantInt forms
from automatically casting to the result type to avoid any similar
problems in the future.

llvm-svn: 353077

2 files changed, 49 insertions, 4 deletions

diff --git a/llvm/unittests/CodeGen/GlobalISel/CSETest.cpp b/llvm/unittests/CodeGen/GlobalISel/CSETest.cpp
index cd6f99bf6e4..02627cae164 100644
--- a/llvm/unittests/CodeGen/GlobalISel/CSETest.cpp
+++ b/llvm/unittests/CodeGen/GlobalISel/CSETest.cpp
@@ -25,6 +25,7 @@ TEST_F(GISelMITest, TestCSE) {
   CSEInfo.analyze(*MF);
   B.setCSEInfo(&CSEInfo);
   CSEMIRBuilder CSEB(B.getState());
+
   CSEB.setInsertPt(*EntryMBB, EntryMBB->begin());
   unsigned AddReg = MRI->createGenericVirtualRegister(s16);
   auto MIBAddCopy =
@@ -54,6 +55,18 @@ TEST_F(GISelMITest, TestCSE) {
   EXPECT_TRUE(&*MIBFP0 == &*MIBFP0_1);
   CSEInfo.print();
 
+  // Make sure buildConstant with a vector type doesn't crash, and the elements
+  // CSE.
+  auto Splat0 = CSEB.buildConstant(LLT::vector(2, s32), 0);
+  EXPECT_EQ(TargetOpcode::G_BUILD_VECTOR, Splat0->getOpcode());
+  EXPECT_EQ(Splat0->getOperand(1).getReg(), Splat0->getOperand(2).getReg());
+  EXPECT_EQ(&*MIBCst, MRI->getVRegDef(Splat0->getOperand(1).getReg()));
+
+  auto FSplat = CSEB.buildFConstant(LLT::vector(2, s32), 1.0);
+  EXPECT_EQ(TargetOpcode::G_BUILD_VECTOR, FSplat->getOpcode());
+  EXPECT_EQ(FSplat->getOperand(1).getReg(), FSplat->getOperand(2).getReg());
+  EXPECT_EQ(&*MIBFP0, MRI->getVRegDef(FSplat->getOperand(1).getReg()));
+
   // Check G_UNMERGE_VALUES
   auto MIBUnmerge = CSEB.buildUnmerge({s32, s32}, Copies[0]);
   auto MIBUnmerge2 = CSEB.buildUnmerge({s32, s32}, Copies[0]);
diff --git a/llvm/unittests/CodeGen/GlobalISel/MachineIRBuilderTest.cpp b/llvm/unittests/CodeGen/GlobalISel/MachineIRBuilderTest.cpp
index ca25ec54d6d..9a2533159be 100644
--- a/llvm/unittests/CodeGen/GlobalISel/MachineIRBuilderTest.cpp
+++ b/llvm/unittests/CodeGen/GlobalISel/MachineIRBuilderTest.cpp
@@ -13,9 +13,6 @@ TEST_F(GISelMITest, TestBuildConstantFConstant) {
   if (!TM)
     return;
 
-  MachineIRBuilder B(*MF);
-  B.setInsertPt(*EntryMBB, EntryMBB->begin());
-
   B.buildConstant(LLT::scalar(32), 42);
   B.buildFConstant(LLT::scalar(32), 1.0);
 
@@ -27,9 +24,44 @@ TEST_F(GISelMITest, TestBuildConstantFConstant) {
   CHECK: [[FCONST0:%[0-9]+]]:_(s32) = G_FCONSTANT float 1.000000e+00
   CHECK: [[CONST1:%[0-9]+]]:_(s32) = G_CONSTANT i32 99
   CHECK: [[VEC0:%[0-9]+]]:_(<2 x s32>) = G_BUILD_VECTOR [[CONST1]]:_(s32), [[CONST1]]:_(s32)
-  CHECK: [[FCONST1:%[0-9]+]]:_(s32) = G_FCONSTANT double 2.000000e+00
+  CHECK: [[FCONST1:%[0-9]+]]:_(s32) = G_FCONSTANT float 2.000000e+00
   CHECK: [[VEC1:%[0-9]+]]:_(<2 x s32>) = G_BUILD_VECTOR [[FCONST1]]:_(s32), [[FCONST1]]:_(s32)
   )";
 
   EXPECT_TRUE(CheckMachineFunction(*MF, CheckStr)) << *MF;
 }
+
+
+#ifdef GTEST_HAS_DEATH_TEST
+#ifndef NDEBUG
+
+TEST_F(GISelMITest, TestBuildConstantFConstantDeath) {
+  if (!TM)
+    return;
+
+  LLVMContext &Ctx = MF->getFunction().getContext();
+  APInt APV32(32, 12345);
+
+  // Test APInt version breaks
+  EXPECT_DEATH(B.buildConstant(LLT::scalar(16), APV32),
+               "creating constant with the wrong size");
+  EXPECT_DEATH(B.buildConstant(LLT::vector(2, 16), APV32),
+               "creating constant with the wrong size");
+
+  // Test ConstantInt version breaks
+  ConstantInt *CI = ConstantInt::get(Ctx, APV32);
+  EXPECT_DEATH(B.buildConstant(LLT::scalar(16), *CI),
+               "creating constant with the wrong size");
+  EXPECT_DEATH(B.buildConstant(LLT::vector(2, 16), *CI),
+               "creating constant with the wrong size");
+
+  APFloat DoubleVal(APFloat::IEEEdouble());
+  ConstantFP *CF = ConstantFP::get(Ctx, DoubleVal);
+  EXPECT_DEATH(B.buildFConstant(LLT::scalar(16), *CF),
+               "creating fconstant with the wrong size");
+  EXPECT_DEATH(B.buildFConstant(LLT::vector(2, 16), *CF),
+               "creating fconstant with the wrong size");
+}
+
+#endif
+#endif