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| author | Dan Gohman <gohman@apple.com> | 2012-02-24 00:09:36 +0000 |
|---|---|---|
| committer | Dan Gohman <gohman@apple.com> | 2012-02-24 00:09:36 +0000 |
| commit | db9538923eb95df48e9a6abe7e3b0ba8435915d7 (patch) | |
| tree | 4cf2df843c044f4dc5a692c3e725ce1f87df7df5 | |
| parent | 6e6b822b51d2716614a2b2ab17a7023d7879ab70 (diff) | |
| download | external_llvm-db9538923eb95df48e9a6abe7e3b0ba8435915d7.zip external_llvm-db9538923eb95df48e9a6abe7e3b0ba8435915d7.tar.gz external_llvm-db9538923eb95df48e9a6abe7e3b0ba8435915d7.tar.bz2 | |
When emitting a cmp with 0 for a lowered select, mask out the high
bits of the value carying the boolean condition, as their contents
are undefined. This fixes rdar://10887484.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151310 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/Target/ARM/ARMISelLowering.cpp | 5 | ||||
| -rw-r--r-- | test/CodeGen/ARM/load_i1_select.ll | 19 |
2 files changed, 24 insertions, 0 deletions
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp index 8a02162..94ddf86 100644 --- a/lib/Target/ARM/ARMISelLowering.cpp +++ b/lib/Target/ARM/ARMISelLowering.cpp @@ -2841,6 +2841,11 @@ SDValue ARMTargetLowering::LowerSELECT(SDValue Op, SelectionDAG &DAG) const { } } + // ARM's BooleanContents value is UndefinedBooleanContent. Mask out the + // undefined bits before doing a full-word comparison with zero. + Cond = DAG.getNode(ISD::AND, dl, Cond.getValueType(), Cond, + DAG.getConstant(1, Cond.getValueType())); + return DAG.getSelectCC(dl, Cond, DAG.getConstant(0, Cond.getValueType()), SelectTrue, SelectFalse, ISD::SETNE); diff --git a/test/CodeGen/ARM/load_i1_select.ll b/test/CodeGen/ARM/load_i1_select.ll new file mode 100644 index 0000000..bdd4081 --- /dev/null +++ b/test/CodeGen/ARM/load_i1_select.ll @@ -0,0 +1,19 @@ +; RUN: llc < %s | FileCheck %s + +target datalayout = "e-p:32:32:32-i1:8:32-i8:8:32-i16:16:32-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:32:64-v128:32:128-a0:0:32-n32-S32" +target triple = "thumbv7-apple-ios0.0.0" + +; Codegen should only compare one bit of the loaded value. +; rdar://10887484 + +; CHECK: foo: +; CHECK: ldrb r[[R0:[0-9]+]], [r0] +; CHECK: tst.w r[[R0]], #1 +define void @foo(i8* %call, double* %p) nounwind { +entry: + %tmp2 = load i8* %call + %tmp3 = trunc i8 %tmp2 to i1 + %cond = select i1 %tmp3, double 2.000000e+00, double 1.000000e+00 + store double %cond, double* %p + ret void +} |