[llvm] r310239 - [SelectionDAG] reset NewNodesMustHaveLegalTypes flag between basic blocks

[Guy Blank via llvm-commits]

Author: guyblank
Date: Sun Aug  6 22:51:14 2017
New Revision: 310239

URL: http://llvm.org/viewvc/llvm-project?rev=310239&view=rev
Log:
[SelectionDAG] reset NewNodesMustHaveLegalTypes flag between basic blocks

The NewNodesMustHaveLegalTypes flag is set to false at the beginning of CodeGenAndEmitDAG, and set to true after legalizing types.
But before calling CodeGenAndEmitDAG we build the DAG for the basic block.
So for the first basic block NewNodesMustHaveLegalTypes would be 'false' during the SDAG building, and for all other basic blocks it would be 'true'.

This patch sets the flag to false before SDAG building each basic block.

Differential Revision:
https://reviews.llvm.org/D33435

Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
    llvm/trunk/test/CodeGen/AArch64/fold-constants.ll

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp?rev=310239&r1=310238&r2=310239&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp Sun Aug  6 22:51:14 2017
@@ -646,6 +646,9 @@ static void reportFastISelFailure(Machin
 void SelectionDAGISel::SelectBasicBlock(BasicBlock::const_iterator Begin,
                                         BasicBlock::const_iterator End,
                                         bool &HadTailCall) {
+  // Allow creating illegal types during DAG building for the basic block.
+  CurDAG->NewNodesMustHaveLegalTypes = false;
+
   // Lower the instructions. If a call is emitted as a tail call, cease emitting
   // nodes for this block.
   for (BasicBlock::const_iterator I = Begin; I != End && !SDB->HasTailCall; ++I) {

Modified: llvm/trunk/test/CodeGen/AArch64/fold-constants.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AArch64/fold-constants.ll?rev=310239&r1=310238&r2=310239&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AArch64/fold-constants.ll (original)
+++ llvm/trunk/test/CodeGen/AArch64/fold-constants.ll Sun Aug  6 22:51:14 2017
@@ -19,9 +19,19 @@ entry:
 
 ; PR25763 - folding constant vector comparisons with sign-extended result
 define <8 x i16> @dotests_458() {
+; CHECK-LABEL: .LCPI1_0:
+; CHECK:       .hword  0                       // 0x0
+; CHECK-NEXT:  .hword  0                       // 0x0
+; CHECK-NEXT:  .hword  65535                   // 0xffff
+; CHECK-NEXT:  .hword  0                       // 0x0
+; CHECK-NEXT:  .hword  0                       // 0x0
+; CHECK-NEXT:  .hword  0                       // 0x0
+; CHECK-NEXT:  .hword  0                       // 0x0
+; CHECK-NEXT:  .hword  0                       // 0x0
+
 ; CHECK-LABEL: dotests_458
-; CHECK:       movi d0, #0x00000000ff0000
-; CHECK-NEXT:  sshll v0.8h, v0.8b, #0
+; CHECK:       adrp    x8, .LCPI1_0
+; CHECK-NEXT:  ldr     q0, [x8, :lo12:.LCPI1_0]
 ; CHECK-NEXT:  ret
 entry:
   %vclz_v.i = call <8 x i8> @llvm.ctlz.v8i8(<8 x i8> <i8 127, i8 38, i8 -1, i8 -128, i8 127, i8 0, i8 0, i8 0>, i1 false) #6