[ARM] Don't promote i1 types in ARM CGP

[samparker]

Summary

Now that we have mixed type sizes, i1 values need to be explicitly handled as we want to avoid promoting these values.

[SjoerdMeijer]

Looks like a straightforward fix to me.

lib/Target/ARM/ARMCodeGenPrepare.cpp

static bool isSupportedType(Value *V) {
 
   // Allow voids and pointers, these won't be promoted.
   if (Ty->isVoidTy() || Ty->isPointerTy())
     return true;
 
   if (auto *Ld = dyn_cast<LoadInst>(V))
     Ty = cast<PointerType>(Ld->getPointerOperandType())->getElementType();
 
-  if (!isa<IntegerType>(Ty))
+  if (!isa<IntegerType>(Ty) ||
+      cast<IntegerType>(V->getType())->getBitWidth() == 1)
     return false;
 
   return LessOrEqualTypeSize(V);
 }
 
 /// Return true if the given value is a source in the use-def chain, producing
 /// a narrow (i8, i16) value. These values will be zext to start the promotion
 /// of the tree to i32. We guarantee that these won't populate the upper bits
 /// of the register. ZExt on the loads will be free, and the same for call
 /// return values because we only accept ones that guarantee a zeroext ret val.
 /// Many arguments will have the zeroext attribute too, so those would be free
 /// too.
 static bool isSource(Value *V) {
   if (!isa<IntegerType>(V->getType()))
     return false;
+
   // TODO Allow zext to be sources.
   if (isa<Argument>(V))
     return true;
   else if (isa<LoadInst>(V))
     return true;
   else if (isa<BitCastInst>(V))
     return true;
   else if (auto *Call = dyn_cast<CallInst>(V))

test/CodeGen/ARM/CGP/arm-cgp-calls.ll

 entry:
   %_Value = getelementptr inbounds %struct.atomic_flag, %struct.atomic_flag* %object, i32 0, i32 0
   %call = tail call arm_aapcscc zeroext i8 @__atomic_exchange_1(i8* %_Value, i8 zeroext 1, i32 5) #1
   %0 = and i8 %call, 1
   %tobool = icmp ne i8 %0, 0
   ret i1 %tobool
 }
 
+; CHECK-LABEL: i1_zeroext_call
+; CHECK: uxt
+define i1 @i1_zeroext_call(i16* %ts, i32 %a, i16* %b, i8* %c) {
+entry:
+  %0 = load i16, i16* %ts, align 2
+  %conv.i860 = trunc i32 %a to i16
+  store i16 %conv.i860, i16* %b, align 2
+  %call.i848 = call zeroext i1 @i1_zeroext(i8* %c, i32 64, i16 zeroext %conv.i860)
+  br i1 %call.i848, label %if.then223, label %if.else227
+
+if.then223:
+  %cmp235 = icmp eq i16 %0, %conv.i860
+  br label %exit
+
+if.else227:
+  %cmp236 = icmp ult i16 %0, %conv.i860
+  br label %exit
+
+exit:
+  %retval = phi i1 [ %cmp235, %if.then223 ], [ %cmp236, %if.else227 ]
+  ret i1 %retval
+}
+
+
 declare i32 @assert(...)
 declare i8 @dummy_i8(i8)
 declare i8 @dummy2(i8*, i8, i8)
 declare i16 @dummy3(i16)
 
 declare dso_local i32 @e(...) local_unnamed_addr #1
 declare dso_local zeroext i16 @f(...) local_unnamed_addr #1
 declare dso_local arm_aapcscc i8 @__atomic_exchange_1(i8*, i8, i32) local_unnamed_addr
 
 declare noalias i16** @func_62(i8 zeroext %p_63, i32 %p_64, i16 signext %p_65, i32* nocapture readnone %p_66)
 declare fastcc signext i16 @safe_sub_func_int16_t_s_s(i16 signext %si2)
 declare dso_local fastcc i64 @safe_sub_func_int64_t_s_s(i64, i64)
 declare dso_local fastcc zeroext i8 @safe_lshift_func(i8 zeroext, i32)
 declare dso_local fastcc zeroext i8 @safe_mul_func_uint8_t_u_u(i8 returned zeroext)
+declare i1 @i1_zeroext(i8*, i32, i16 zeroext)

test/CodeGen/ARM/CGP/arm-cgp-casts.ll

   %trunc = trunc i16 %sub to i8
   %add = add nuw i8 %d, %trunc
   br label %if.end
 
 if.end:
   %retval = phi i8 [ 0, %entry ], [ %add, %if.then ]
   ret i8 %retval
 }
+
+define i32 @bitcast_i1(i16 zeroext %a, i32 %b, i32 %c) {
+entry:
+  %0 = bitcast i1 1 to i1
+  %1 = trunc i16 %a to i1
+  %cmp = icmp eq i1 %1, %0
+  br i1 %cmp, label %if.then, label %exit
+
+if.then:
+  %conv = zext i1 %0 to i16
+  %conv1 = zext i1 %1 to i16
+  %cmp1 = icmp uge i16 %conv, %conv1
+  %select = select i1 %cmp1, i32 %b, i32 %c
+  br label %exit
+
+exit:
+  %retval = phi i32 [ %select, %if.then ], [ 0, %entry ]
+  ret i32 %retval
+}