commit 85d9d5d4bbc6ef1a8382df21d92bc6dc0bed4057
author Antonio Maiorano <amaiorano@google.com> Mon Oct 19 14:37:53 2020 -0400
committer Antonio Maiorano <amaiorano@google.com> Tue Oct 20 20:52:52 2020 +0000
tree 561e850da8ae96b7b347963ab5b47e92e4281d62
parent ee18f390eeadf44413a596881be3d45637e2243d

Subzero: workaround bad codegen for Windows x86 at Om1 optimization level

See the referenced bug for the gory details. For now, this makes it so
that Subzero's codegen doesn't crash even in the simple ReactorUnitTest
cases.

Bug: b/171222930
Change-Id: Ie22a91d7e3e4f3d940b7b9120067469ac4264020
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/49388
Kokoro-Result: kokoro <noreply+kokoro@google.com>
Tested-by: Antonio Maiorano <amaiorano@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>

third_party/subzero/src/IceTargetLoweringX86BaseImpl.h

diff --git a/third_party/subzero/src/IceTargetLoweringX86BaseImpl.h b/third_party/subzero/src/IceTargetLoweringX86BaseImpl.h
index e231ce9..ab90fad 100644
--- a/third_party/subzero/src/IceTargetLoweringX86BaseImpl.h
+++ b/third_party/subzero/src/IceTargetLoweringX86BaseImpl.h
@@ -614,7 +614,8 @@
   genTargetHelperCalls();
 
   // Do not merge Alloca instructions, and lay out the stack.
-  static constexpr bool SortAndCombineAllocas = false;
+  // static constexpr bool SortAndCombineAllocas = false;
+  static constexpr bool SortAndCombineAllocas = true; // TODO(b/171222930): Fix Win32 bug when this is false
   Func->processAllocas(SortAndCombineAllocas);
   Func->dump("After Alloca processing");