From: Simon Pilgrim <llvm-dev@redking.me.uk>
Date: Wed, 8 May 2019 11:22:10 +0000 (+0000)
Subject: [LegalizeDAG] Assert non-power-of-2 load/store op splits are in range. NFCI.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=7c30385fc1864606dfb785d8fb37f27371020cf6;p=llvm

[LegalizeDAG] Assert non-power-of-2 load/store op splits are in range. NFCI.

Fixes static analyzer undefined/out-of-range shift warnings.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@360245 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index 3c362177ce4..f5a1a8cd084 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -539,7 +539,9 @@ void SelectionDAGLegalize::LegalizeStoreOps(SDNode *Node) {
   } else if (StWidth & (StWidth - 1)) {
     // If not storing a power-of-2 number of bits, expand as two stores.
     assert(!StVT.isVector() && "Unsupported truncstore!");
-    unsigned RoundWidth = 1 << Log2_32(StWidth);
+    unsigned LogStWidth = Log2_32(StWidth);
+    assert(LogStWidth < 32);
+    unsigned RoundWidth = 1 << LogStWidth;
     assert(RoundWidth < StWidth);
     unsigned ExtraWidth = StWidth - RoundWidth;
     assert(ExtraWidth < RoundWidth);
@@ -753,7 +755,9 @@ void SelectionDAGLegalize::LegalizeLoadOps(SDNode *Node) {
   } else if (SrcWidth & (SrcWidth - 1)) {
     // If not loading a power-of-2 number of bits, expand as two loads.
     assert(!SrcVT.isVector() && "Unsupported extload!");
-    unsigned RoundWidth = 1 << Log2_32(SrcWidth);
+    unsigned LogSrcWidth = Log2_32(SrcWidth);
+    assert(LogSrcWidth < 32);
+    unsigned RoundWidth = 1 << LogSrcWidth;
     assert(RoundWidth < SrcWidth);
     unsigned ExtraWidth = SrcWidth - RoundWidth;
     assert(ExtraWidth < RoundWidth);