From 68d1052dc355480e7c8c2bf03ad1309a4a97a7f9 Mon Sep 17 00:00:00 2001
From: Thomas Lively <tlively@google.com>
Date: Thu, 31 Jan 2019 23:22:39 +0000
Subject: [PATCH] [WebAssembly] Fix a regression selecting negative
 build_vector lanes

Summary:
The custom lowering introduced in rL352592 creates build_vector nodes
with negative i32 operands, but these operands did not meet the value
range constraints necessary to match build_vector nodes. This CL fixes
the issue by removing the unnecessary constraints.

Reviewers: aheejin

Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, sunfish

Differential Revision: https://reviews.llvm.org/D57481

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@352813 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/WebAssembly/WebAssemblyInstrSIMD.td | 2 +-
 test/CodeGen/WebAssembly/simd-build-vector.ll  | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/Target/WebAssembly/WebAssemblyInstrSIMD.td b/lib/Target/WebAssembly/WebAssemblyInstrSIMD.td
index b7ecd49c793..ab0f48c9a1e 100644
--- a/lib/Target/WebAssembly/WebAssemblyInstrSIMD.td
+++ b/lib/Target/WebAssembly/WebAssemblyInstrSIMD.td
@@ -30,7 +30,7 @@ defm "" : ARGUMENT<V128, v2f64>;
 // Constrained immediate argument types
 foreach SIZE = [8, 16] in
 def ImmI#SIZE : ImmLeaf<i32,
-  "return ((uint64_t)Imm & ((1UL << "#SIZE#") - 1)) == (uint64_t)Imm;"
+  "return -(1 << ("#SIZE#" - 1)) <= Imm && Imm < (1 << ("#SIZE#" - 1));"
 >;
 foreach SIZE = [2, 4, 8, 16, 32] in
 def LaneIdx#SIZE : ImmLeaf<i32, "return 0 <= Imm && Imm < "#SIZE#";">;
diff --git a/test/CodeGen/WebAssembly/simd-build-vector.ll b/test/CodeGen/WebAssembly/simd-build-vector.ll
index ab08ef4be7d..41a320c92f7 100644
--- a/test/CodeGen/WebAssembly/simd-build-vector.ll
+++ b/test/CodeGen/WebAssembly/simd-build-vector.ll
@@ -23,12 +23,12 @@ define <8 x i16> @same_const_one_replaced_i8x16(i16 %x) {
 
 ; CHECK-LABEL: different_const_one_replaced_i8x16:
 ; CHECK-NEXT:  .functype       different_const_one_replaced_i8x16 (i32) -> (v128)
-; CHECK-NEXT:  v128.const      $push[[L0:[0-9]+]]=, 1, 2, 3, 4, 5, 0, 7, 8
+; CHECK-NEXT:  v128.const      $push[[L0:[0-9]+]]=, 1, -2, 3, -4, 5, 0, 7, -8
 ; CHECK-NEXT:  i16x8.replace_lane      $push[[L1:[0-9]+]]=, $pop[[L0]], 5, $0
 ; CHECK-NEXT:  return          $pop[[L1]]
 define <8 x i16> @different_const_one_replaced_i8x16(i16 %x) {
   %v = insertelement
-    <8 x i16> <i16 1, i16 2, i16 3, i16 4, i16 5, i16 6, i16 7, i16 8>,
+    <8 x i16> <i16 1, i16 -2, i16 3, i16 -4, i16 5, i16 -6, i16 7, i16 -8>,
     i16 %x,
     i32 5
   ret <8 x i16> %v
-- 
2.40.0