[GlobalISel] Avoid translating synthetic constants to new G_CONSTANTS.

Currently, we create a G_CONSTANT for every "synthetic" integer
constant operand (for instance, for the G_GEP offset).
Instead, share the G_CONSTANTs we might have created by going through
the ValueToVReg machinery.

When we're emitting synthetic constants, we do need to get Constants from
the context.  One could argue that we shouldn't modify the context at
all (for instance, this means that we're going to use a tad more memory
if the constant wasn't used elsewhere), but constants are mostly
harmless.  We currently do this for extractvalue and all.

For constant fcmp, this does mean we'll emit an extra COPY, which is not
necessarily more optimal than an extra materialized constant.
But that preserves the current intended design of uniqued G_CONSTANTs,
and the rematerialization problem exists elsewhere and should be
resolved with a single coherent solution.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@297875 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/GlobalISel/IRTranslator.cpp b/lib/CodeGen/GlobalISel/IRTranslator.cpp
index 353c4a22fe6b635e39aa7aa4ab6c273f9e79572e..7b09fd815ab9eb7cdf0236ad07a9da9bfddbacfa 100644 (file)
--- a/lib/CodeGen/GlobalISel/IRTranslator.cpp
+++ b/lib/CodeGen/GlobalISel/IRTranslator.cpp
@@ -190,9 +190,11 @@ bool IRTranslator::translateCompare(const User &U,
   if (CmpInst::isIntPredicate(Pred))
     MIRBuilder.buildICmp(Pred, Res, Op0, Op1);
   else if (Pred == CmpInst::FCMP_FALSE)
-    MIRBuilder.buildConstant(Res, 0);
-  else if  (Pred == CmpInst::FCMP_TRUE)
-    MIRBuilder.buildConstant(Res, 1);
+    MIRBuilder.buildCopy(
+        Res, getOrCreateVReg(*Constant::getNullValue(CI->getType())));
+  else if (Pred == CmpInst::FCMP_TRUE)
+    MIRBuilder.buildCopy(
+        Res, getOrCreateVReg(*Constant::getAllOnesValue(CI->getType())));
   else
     MIRBuilder.buildFCmp(Pred, Res, Op0, Op1);
 
@@ -426,9 +428,10 @@ bool IRTranslator::translateGetElementPtr(const User &U,
 
   Value &Op0 = *U.getOperand(0);
   unsigned BaseReg = getOrCreateVReg(Op0);
-  LLT PtrTy = getLLTForType(*Op0.getType(), *DL);
-  unsigned PtrSize = DL->getPointerSizeInBits(PtrTy.getAddressSpace());
-  LLT OffsetTy = LLT::scalar(PtrSize);
+  Type *PtrIRTy = Op0.getType();
+  LLT PtrTy = getLLTForType(*PtrIRTy, *DL);
+  Type *OffsetIRTy = DL->getIntPtrType(PtrIRTy);
+  LLT OffsetTy = getLLTForType(*OffsetIRTy, *DL);
 
   int64_t Offset = 0;
   for (gep_type_iterator GTI = gep_type_begin(&U), E = gep_type_end(&U);
@@ -450,8 +453,8 @@ bool IRTranslator::translateGetElementPtr(const User &U,
 
       if (Offset != 0) {
         unsigned NewBaseReg = MRI->createGenericVirtualRegister(PtrTy);
-        unsigned OffsetReg = MRI->createGenericVirtualRegister(OffsetTy);
-        MIRBuilder.buildConstant(OffsetReg, Offset);
+        unsigned OffsetReg =
+            getOrCreateVReg(*ConstantInt::get(OffsetIRTy, Offset));
         MIRBuilder.buildGEP(NewBaseReg, BaseReg, OffsetReg);
 
         BaseReg = NewBaseReg;
@@ -459,8 +462,8 @@ bool IRTranslator::translateGetElementPtr(const User &U,
       }
 
       // N = N + Idx * ElementSize;
-      unsigned ElementSizeReg = MRI->createGenericVirtualRegister(OffsetTy);
-      MIRBuilder.buildConstant(ElementSizeReg, ElementSize);
+      unsigned ElementSizeReg =
+          getOrCreateVReg(*ConstantInt::get(OffsetIRTy, ElementSize));
 
       unsigned IdxReg = getOrCreateVReg(*Idx);
       if (MRI->getType(IdxReg) != OffsetTy) {
@@ -479,8 +482,7 @@ bool IRTranslator::translateGetElementPtr(const User &U,
   }
 
   if (Offset != 0) {
-    unsigned OffsetReg = MRI->createGenericVirtualRegister(OffsetTy);
-    MIRBuilder.buildConstant(OffsetReg, Offset);
+    unsigned OffsetReg = getOrCreateVReg(*ConstantInt::get(OffsetIRTy, Offset));
     MIRBuilder.buildGEP(getOrCreateVReg(U), BaseReg, OffsetReg);
     return true;
   }
@@ -561,8 +563,8 @@ bool IRTranslator::translateOverflowIntrinsic(const CallInst &CI, unsigned Op,
                  .addUse(getOrCreateVReg(*CI.getOperand(1)));
 
   if (Op == TargetOpcode::G_UADDE || Op == TargetOpcode::G_USUBE) {
-    unsigned Zero = MRI->createGenericVirtualRegister(s1);
-    EntryBuilder.buildConstant(Zero, 0);
+    unsigned Zero = getOrCreateVReg(
+        *Constant::getNullValue(Type::getInt1Ty(CI.getContext())));
     MIB.addUse(Zero);
   }
 
@@ -914,7 +916,8 @@ bool IRTranslator::translateAlloca(const User &U,
 
   unsigned NumElts = getOrCreateVReg(*AI.getArraySize());
 
-  LLT IntPtrTy = LLT::scalar(DL->getPointerSizeInBits());
+  Type *IntPtrIRTy = DL->getIntPtrType(AI.getType());
+  LLT IntPtrTy = getLLTForType(*IntPtrIRTy, *DL);
   if (MRI->getType(NumElts) != IntPtrTy) {
     unsigned ExtElts = MRI->createGenericVirtualRegister(IntPtrTy);
     MIRBuilder.buildZExtOrTrunc(ExtElts, NumElts);
@@ -922,8 +925,8 @@ bool IRTranslator::translateAlloca(const User &U,
   }
 
   unsigned AllocSize = MRI->createGenericVirtualRegister(IntPtrTy);
-  unsigned TySize = MRI->createGenericVirtualRegister(IntPtrTy);
-  MIRBuilder.buildConstant(TySize, -DL->getTypeAllocSize(Ty));
+  unsigned TySize =
+      getOrCreateVReg(*ConstantInt::get(IntPtrIRTy, -DL->getTypeAllocSize(Ty)));
   MIRBuilder.buildMul(AllocSize, NumElts, TySize);
 
   LLT PtrTy = getLLTForType(*AI.getType(), *DL);

diff --git a/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll b/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll
index 88cb25546916eb40a780b18728d5d7aa58171bee..6e0b1e632ffd6be5a121fbc0452a44daa30eff3f 100644 (file)
--- a/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll
+++ b/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll
@@ -1064,8 +1064,10 @@ define void @float_comparison(float* %a.addr, float* %b.addr, i1* %bool.addr) {
 }
 
 ; CHECK-LABEL: name: trivial_float_comparison
-; CHECK: [[R1:%[0-9]+]](s1) = G_CONSTANT i1 false
-; CHECK: [[R2:%[0-9]+]](s1) = G_CONSTANT i1 true
+; CHECK: [[ENTRY_R1:%[0-9]+]](s1) = G_CONSTANT i1 false
+; CHECK: [[ENTRY_R2:%[0-9]+]](s1) = G_CONSTANT i1 true
+; CHECK: [[R1:%[0-9]+]](s1) = COPY [[ENTRY_R1]](s1)
+; CHECK: [[R2:%[0-9]+]](s1) = COPY [[ENTRY_R2]](s1)
 ; CHECK: G_ADD [[R1]], [[R2]]
 define i1 @trivial_float_comparison(double %a, double %b) {
   %r1 = fcmp false double %a, %b

diff --git a/test/CodeGen/AArch64/GlobalISel/dynamic-alloca.ll b/test/CodeGen/AArch64/GlobalISel/dynamic-alloca.ll
index c52a575488dbd328bec4800ed3a263335ba6258b..196910e96ce3e68f70d46687e9647d9301558155 100644 (file)
--- a/test/CodeGen/AArch64/GlobalISel/dynamic-alloca.ll
+++ b/test/CodeGen/AArch64/GlobalISel/dynamic-alloca.ll
@@ -2,8 +2,8 @@
 
 ; CHECK-LABEL: name: test_simple_alloca
 ; CHECK: [[NUMELTS:%[0-9]+]](s32) = COPY %w0
-; CHECK: [[NUMELTS_64:%[0-9]+]](s64) = G_ZEXT [[NUMELTS]](s32)
 ; CHECK: [[TYPE_SIZE:%[0-9]+]](s64) = G_CONSTANT i64 -1
+; CHECK: [[NUMELTS_64:%[0-9]+]](s64) = G_ZEXT [[NUMELTS]](s32)
 ; CHECK: [[NUMBYTES:%[0-9]+]](s64) = G_MUL [[NUMELTS_64]], [[TYPE_SIZE]]
 ; CHECK: [[SP_TMP:%[0-9]+]](p0) = COPY %sp
 ; CHECK: [[ALLOC:%[0-9]+]](p0) = G_GEP [[SP_TMP]], [[NUMBYTES]]
@@ -18,8 +18,8 @@ define i8* @test_simple_alloca(i32 %numelts) {
 
 ; CHECK-LABEL: name: test_aligned_alloca
 ; CHECK: [[NUMELTS:%[0-9]+]](s32) = COPY %w0
-; CHECK: [[NUMELTS_64:%[0-9]+]](s64) = G_ZEXT [[NUMELTS]](s32)
 ; CHECK: [[TYPE_SIZE:%[0-9]+]](s64) = G_CONSTANT i64 -1
+; CHECK: [[NUMELTS_64:%[0-9]+]](s64) = G_ZEXT [[NUMELTS]](s32)
 ; CHECK: [[NUMBYTES:%[0-9]+]](s64) = G_MUL [[NUMELTS_64]], [[TYPE_SIZE]]
 ; CHECK: [[SP_TMP:%[0-9]+]](p0) = COPY %sp
 ; CHECK: [[ALLOC:%[0-9]+]](p0) = G_GEP [[SP_TMP]], [[NUMBYTES]]
@@ -34,8 +34,8 @@ define i8* @test_aligned_alloca(i32 %numelts) {
 
 ; CHECK-LABEL: name: test_natural_alloca
 ; CHECK: [[NUMELTS:%[0-9]+]](s32) = COPY %w0
-; CHECK: [[NUMELTS_64:%[0-9]+]](s64) = G_ZEXT [[NUMELTS]](s32)
 ; CHECK: [[TYPE_SIZE:%[0-9]+]](s64) = G_CONSTANT i64 -16
+; CHECK: [[NUMELTS_64:%[0-9]+]](s64) = G_ZEXT [[NUMELTS]](s32)
 ; CHECK: [[NUMBYTES:%[0-9]+]](s64) = G_MUL [[NUMELTS_64]], [[TYPE_SIZE]]
 ; CHECK: [[SP_TMP:%[0-9]+]](p0) = COPY %sp
 ; CHECK: [[ALLOC:%[0-9]+]](p0) = G_GEP [[SP_TMP]], [[NUMBYTES]]

diff --git a/test/CodeGen/AArch64/GlobalISel/translate-gep.ll b/test/CodeGen/AArch64/GlobalISel/translate-gep.ll
index 14dbc7c3c31a985d219754a535d0607bd1cbfbf6..e4c18757418d0a342ebca28ff1b059f8fcbd4233 100644 (file)
--- a/test/CodeGen/AArch64/GlobalISel/translate-gep.ll
+++ b/test/CodeGen/AArch64/GlobalISel/translate-gep.ll
@@ -58,8 +58,8 @@ define i32* @const_then_var(%type1* %addr, i64 %idx) {
 ; CHECK: [[BASE:%[0-9]+]](p0) = COPY %x0
 ; CHECK: [[IDX:%[0-9]+]](s64) = COPY %x1
 ; CHECK: [[OFFSET1:%[0-9]+]](s64) = G_CONSTANT i64 272
-; CHECK: [[BASE1:%[0-9]+]](p0) = G_GEP [[BASE]], [[OFFSET1]](s64)
 ; CHECK: [[SIZE:%[0-9]+]](s64) = G_CONSTANT i64 4
+; CHECK: [[BASE1:%[0-9]+]](p0) = G_GEP [[BASE]], [[OFFSET1]](s64)
 ; CHECK: [[OFFSET2:%[0-9]+]](s64) = G_MUL [[SIZE]], [[IDX]]
 ; CHECK: [[BASE2:%[0-9]+]](p0) = G_GEP [[BASE1]], [[OFFSET2]](s64)
 ; CHECK: [[RES:%[0-9]+]](p0) = COPY [[BASE2]](p0)
@@ -74,9 +74,9 @@ define i32* @var_then_const(%type1* %addr, i64 %idx) {
 ; CHECK: [[BASE:%[0-9]+]](p0) = COPY %x0
 ; CHECK: [[IDX:%[0-9]+]](s64) = COPY %x1
 ; CHECK: [[SIZE:%[0-9]+]](s64) = G_CONSTANT i64 64
+; CHECK: [[OFFSET2:%[0-9]+]](s64) = G_CONSTANT i64 40
 ; CHECK: [[OFFSET1:%[0-9]+]](s64) = G_MUL [[SIZE]], [[IDX]]
 ; CHECK: [[BASE1:%[0-9]+]](p0) = G_GEP [[BASE]], [[OFFSET1]](s64)
-; CHECK: [[OFFSET2:%[0-9]+]](s64) = G_CONSTANT i64 40
 ; CHECK: [[BASE2:%[0-9]+]](p0) = G_GEP [[BASE1]], [[OFFSET2]](s64)
 ; CHECK: %x0 = COPY [[BASE2]](p0)