[llvm] r224717 - [CodeGenPrepare] Handle properly the promotion of operands when this does not

[Quentin Colombet]

Author: qcolombet
Date: Mon Dec 22 12:11:52 2014
New Revision: 224717

URL: http://llvm.org/viewvc/llvm-project?rev=224717&view=rev
Log:
[CodeGenPrepare] Handle properly the promotion of operands when this does not
generate instructions.

Fixes PR21978.
Related to <rdar://problem/18310086>

Modified:
    llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp
    llvm/trunk/test/CodeGen/X86/codegen-prepare-extload.ll

Modified: llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp?rev=224717&r1=224716&r2=224717&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp (original)
+++ llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp Mon Dec 22 12:11:52 2014
@@ -2069,9 +2069,13 @@ Value *TypePromotionHelper::promoteOpera
     if (!ExtForOpnd) {
       // If yes, create a new one.
       DEBUG(dbgs() << "More operands to ext\n");
-      ExtForOpnd =
-          cast<Instruction>(IsSExt ? TPT.createSExt(Ext, Opnd, Ext->getType())
-                                   : TPT.createZExt(Ext, Opnd, Ext->getType()));
+      Value *ValForExtOpnd = IsSExt ? TPT.createSExt(Ext, Opnd, Ext->getType())
+        : TPT.createZExt(Ext, Opnd, Ext->getType());
+      if (!isa<Instruction>(ValForExtOpnd)) {
+        TPT.setOperand(ExtOpnd, OpIdx, ValForExtOpnd);
+        continue;
+      }
+      ExtForOpnd = cast<Instruction>(ValForExtOpnd);
       ++CreatedInsts;
     }
     if (Exts)

Modified: llvm/trunk/test/CodeGen/X86/codegen-prepare-extload.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/codegen-prepare-extload.ll?rev=224717&r1=224716&r2=224717&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/codegen-prepare-extload.ll (original)
+++ llvm/trunk/test/CodeGen/X86/codegen-prepare-extload.ll Mon Dec 22 12:11:52 2014
@@ -336,3 +336,28 @@ entry:
   %b = zext <2 x i32> %a to <2 x i64>
   ret void
 }
+
+ at a = common global i32 0, align 4
+ at c = common global [2 x i32] zeroinitializer, align 4
+
+; PR21978.
+; Make sure we support promotion of operands that produces a Value as opposed
+; to an instruction.
+; This used to cause a crash.
+; OPTALL-LABEL: @promotionOfArgEndsUpInValue
+; OPTALL: [[LD:%[a-zA-Z_0-9-]+]] = load i16* %addr
+
+; OPT-NEXT: [[SEXT:%[a-zA-Z_0-9-]+]] = sext i16 [[LD]] to i32
+; OPT-NEXT: [[RES:%[a-zA-Z_0-9-]+]] = add nuw nsw i32 [[SEXT]], zext (i1 icmp ne (i32* getelementptr inbounds ([2 x i32]* @c, i64 0, i64 1), i32* @a) to i32)
+;
+; DISABLE-NEXT: [[ADD:%[a-zA-Z_0-9-]+]] = add nuw nsw i16 [[LD]], zext (i1 icmp ne (i32* getelementptr inbounds ([2 x i32]* @c, i64 0, i64 1), i32* @a) to i16)
+; DISABLE-NEXT: [[RES:%[a-zA-Z_0-9-]+]] = sext i16 [[ADD]] to i32
+;
+; OPTALL-NEXT: ret i32 [[RES]]
+define i32 @promotionOfArgEndsUpInValue(i16* %addr) {
+entry:
+  %val = load i16* %addr
+  %add = add nuw nsw i16 %val, zext (i1 icmp ne (i32* getelementptr inbounds ([2 x i32]* @c, i64 0, i64 1), i32* @a) to i16)
+  %conv3 = sext i16 %add to i32
+  ret i32 %conv3
+}