[llvm] r318638 - [CGP] Fix the crash caused by enable of complex addr mode

[Serguei Katkov via llvm-commits]

Author: skatkov
Date: Sun Nov 19 21:42:36 2017
New Revision: 318638

URL: http://llvm.org/viewvc/llvm-project?rev=318638&view=rev
Log:
[CGP] Fix the crash caused by enable of complex addr mode

We must collect all AddModes even if they are the same.
This is due to Original value is different but we need all original
values collected as they are used as anchors in common phi finding.

Reviewers: john.brawn, reames
Reviewed By: john.brawn
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D40166

Modified:
    llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp
    llvm/trunk/test/Transforms/CodeGenPrepare/X86/sink-addrmode-base.ll

Modified: llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp?rev=318638&r1=318637&r2=318638&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp (original)
+++ llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp Sun Nov 19 21:42:36 2017
@@ -2800,15 +2800,11 @@ public:
     else if (DifferentField != ThisDifferentField)
       DifferentField = ExtAddrMode::MultipleFields;
 
-    // If this AddrMode is the same as all the others then everything is fine
-    // (which should only happen when there is actually only one AddrMode).
-    if (DifferentField == ExtAddrMode::NoField) {
-      assert(AddrModes.size() == 1);
-      return true;
-    }
-
     // If NewAddrMode differs in only one dimension then we can handle it by
-    // inserting a phi/select later on.
+    // inserting a phi/select later on. Even if NewAddMode is the same
+    // we still need to collect it due to original value is different.
+    // And later we will need all original values as anchors during
+    // finding the common Phi node.
     if (DifferentField != ExtAddrMode::MultipleFields) {
       AddrModes.emplace_back(NewAddrMode);
       return true;
@@ -2829,7 +2825,7 @@ public:
       return false;
 
     // A single AddrMode can trivially be combined.
-    if (AddrModes.size() == 1)
+    if (AddrModes.size() == 1 || DifferentField == ExtAddrMode::NoField)
       return true;
 
     // If the AddrModes we collected are all just equal to the value they are

Modified: llvm/trunk/test/Transforms/CodeGenPrepare/X86/sink-addrmode-base.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/CodeGenPrepare/X86/sink-addrmode-base.ll?rev=318638&r1=318637&r2=318638&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/CodeGenPrepare/X86/sink-addrmode-base.ll (original)
+++ llvm/trunk/test/Transforms/CodeGenPrepare/X86/sink-addrmode-base.ll Sun Nov 19 21:42:36 2017
@@ -473,3 +473,38 @@ fallthrough:
   %v = load i64 , i64* %p1, align 8
   ret i64 %v
 }
+
+; The same two addr modes by different paths
+define i32 @test18(i1 %cond1, i1 %cond2, i64* %b1, i64* %b2) {
+; CHECK-LABEL: @test18
+entry:
+  %g1 = getelementptr inbounds i64, i64* %b2, i64 5
+  %bc1 = bitcast i64* %g1 to i32*
+  br i1 %cond1, label %if.then1, label %if.then2
+
+if.then1:
+  %g2 = getelementptr inbounds i64, i64* %b1, i64 5
+  %bc2 = bitcast i64* %g2 to i32*
+  br label %fallthrough
+
+if.then2:
+  %bc1_1 = bitcast i64* %g1 to i32*
+  br i1 %cond2, label %fallthrough, label %if.then3
+
+if.then3:
+  %bc1_2 = bitcast i64* %g1 to i32*
+  br label %fallthrough
+
+fallthrough:
+; CHECK-YES: sunk_phi
+; CHECK-NO-LABEL: fallthrough:
+; CHECK-NO: phi
+; CHECK-NO-NEXT: load
+  %c = phi i32* [%bc2, %if.then1], [%bc1_1, %if.then2], [%bc1_2, %if.then3]
+  %v1 = load i32, i32* %c, align 4
+  %g1_1 = getelementptr inbounds i64, i64* %b2, i64 5
+  %bc1_1_1 = bitcast i64* %g1_1 to i32*
+  %v2 = load i32, i32* %bc1_1_1, align 4
+  %v = add i32 %v1, %v2
+  ret i32 %v
+}