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authorChris Lattner <sabre@nondot.org>2008-05-24 03:59:33 +0000
committerChris Lattner <sabre@nondot.org>2008-05-24 03:59:33 +0000
commit60301608f8fac2e476db250797b533bbe415b404 (patch)
tree37f9b087fc0108200daa4b94472226a1800cd165
parenta31593901de573813d1d8e7884a152011641a713 (diff)
Fix PR2358 by resolving calls with undef arguments to overdefined.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51535 91177308-0d34-0410-b5e6-96231b3b80d8
-rw-r--r--lib/Transforms/Scalar/SCCP.cpp6
-rw-r--r--test/Transforms/SCCP/2008-05-23-UndefCallFold.ll14
2 files changed, 20 insertions, 0 deletions
diff --git a/lib/Transforms/Scalar/SCCP.cpp b/lib/Transforms/Scalar/SCCP.cpp
index 79cda33f79..da715acd29 100644
--- a/lib/Transforms/Scalar/SCCP.cpp
+++ b/lib/Transforms/Scalar/SCCP.cpp
@@ -1370,6 +1370,12 @@ bool SCCPSolver::ResolvedUndefsIn(Function &F) {
else
markOverdefined(LV, I);
return true;
+ case Instruction::Call:
+ // If a call has an undef result, it is because it is constant foldable
+ // but one of the inputs was undef. Just force the result to
+ // overdefined.
+ markOverdefined(LV, I);
+ return true;
}
}
diff --git a/test/Transforms/SCCP/2008-05-23-UndefCallFold.ll b/test/Transforms/SCCP/2008-05-23-UndefCallFold.ll
new file mode 100644
index 0000000000..f85a36260e
--- /dev/null
+++ b/test/Transforms/SCCP/2008-05-23-UndefCallFold.ll
@@ -0,0 +1,14 @@
+; RUN: llvm-as < %s | opt -sccp | llvm-dis | not grep {ret i32 undef}
+; PR2358
+target datalayout =
+"e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
+target triple = "i686-pc-linux-gnu"
+
+define i32 @x(i32 %b) {
+entry:
+ %val = call i32 @llvm.cttz.i32(i32 undef)
+ ret i32 %val
+}
+
+declare i32 @llvm.cttz.i32(i32)
+