Move workaround for swifterror miscompile earlier

Thank you, Arnold for noting this miscompile on x86!

Author: DougGregor

lib/IRGen/IRGenSIL.cpp

@@ -3787,6 +3787,13 @@ void IRGenSILFunction::visitFullApplySite(FullApplySite site) {
 
     // If the error value is non-null, branch to the error destination.
     auto hasError = Builder.CreateICmpNE(errorValue, nullError);
+
+    // Create a dummy use of 'errorValue' in the catch BB to workaround an
+    // LLVM miscompile that ends up taking the wrong branch if there are no
+    // uses of 'errorValue' in the catch block.
+    // FIXME: Remove this when the following radar is fixed: rdar://116636601
+    Builder.CreatePtrToInt(errorValue, IGM.IntPtrTy);
+
     Builder.CreateCondBr(hasError,
                          typedErrorLoadBB ? typedErrorLoadBB : errorDest.bb,
                          normalDest.bb);
@@ -3806,12 +3813,6 @@ void IRGenSILFunction::visitFullApplySite(FullApplySite site) {
     } else {
       Builder.emitBlock(typedErrorLoadBB);
 
-      // Create a dummy use of 'errorValue' in the catch BB to workaround an
-      // LLVM miscompile that ends up taking the wrong branch if there are no
-      // uses of 'errorValue' in the catch block.
-      // FIXME: Remove this when the following radar is fixed: rdar://116636601
-      Builder.CreatePtrToInt(errorValue, IGM.IntPtrTy);
-
       auto &ti = cast<LoadableTypeInfo>(IGM.getTypeInfo(errorType));
       Explosion errorValue;
       ti.loadAsTake(*this, getCalleeTypedErrorResultSlot(errorType), errorValue);

test/IRGen/errors.sil

@@ -83,6 +83,7 @@ entry(%0 : $AnyObject):
   // CHECK-native-NEXT: [[RESULT:%.*]] = call swiftcc ptr @try_apply_helper(ptr %0, ptr swiftself undef, ptr noalias nocapture [[SWIFTERROR]]{{( )?}}dereferenceable({{.}}) [[ERRORSLOT]])
   // CHECK-NEXT: [[ERR:%.*]] = load ptr, ptr [[ERRORSLOT]], align
   // CHECK-NEXT: [[T0:%.*]] = icmp ne ptr [[ERR]], null
+  // CHECK-NEXT: ptrtoint ptr [[ERR]] to i
   // CHECK-NEXT: br i1 [[T0]],
   %1 = function_ref @try_apply_helper : $@convention(thin) (@owned AnyObject) -> (@owned AnyObject, @error Error)
   try_apply %1(%0) : $@convention(thin) (@owned AnyObject) -> (@owned AnyObject, @error Error),

test/IRGen/unmanaged_objc_throw_func.swift

@@ -24,13 +24,14 @@ import Foundation
     // CHECK-NEXT: call void @llvm.objc.release(ptr %[[T4]])
     // CHECK-NEXT: ret ptr %[[T4]]
     let arr = [1] as CFArray
-    return Unmanaged.passUnretained(arr) 
-  } 
+    return Unmanaged.passUnretained(arr)
+  }
 }
 
 // CHECK: %[[T0:.+]] = call swiftcc ptr @"$s25unmanaged_objc_throw_func1CC22returnUnmanagedCFArrays0F0VySo0G3RefaGyKF"
 // CHECK-NEXT: %[[T2:.+]] = load ptr, ptr %swifterror, align {{[0-9]+}}
 // CHECK-NEXT: %[[T3:.+]] = icmp ne ptr %[[T2]], null
+// CHECK-NEXT: ptrtoint ptr %[[T2]] to i
 // CHECK-NEXT: br i1 %[[T3]], label %[[L1:.+]], label %[[L2:.+]]
 
 // CHECK: [[L2]]:                                     ; preds = %entry