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ARM: do not add a regmask for TAILJUMPs

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The jump doesn't really kill the registers, the following call does but
we never get back anyway.
This avoids some verify-machineinstrs problems when TAILJUMPs are
if-converted.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191962 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Matthias Braun 2013-10-04 16:52:54 +00:00
parent e1bde51d63
commit 4e54f41d6c
2 changed files with 53 additions and 16 deletions
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34
lib/Target/ARM/ARMISelLowering.cpp
View File

@ -1779,24 +1779,26 @@ ARMTargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
RegsToPass[i].second.getValueType()));
// Add a register mask operand representing the call-preserved registers.
const uint32_t *Mask;
const TargetRegisterInfo *TRI = getTargetMachine().getRegisterInfo();
const ARMBaseRegisterInfo *ARI = static_cast<const ARMBaseRegisterInfo*>(TRI);
if (isThisReturn) {
// For 'this' returns, use the R0-preserving mask if applicable
Mask = ARI->getThisReturnPreservedMask(CallConv);
if (!Mask) {
// Set isThisReturn to false if the calling convention is not one that
// allows 'returned' to be modeled in this way, so LowerCallResult does
// not try to pass 'this' straight through
isThisReturn = false;
if (!isTailCall) {
const uint32_t *Mask;
const TargetRegisterInfo *TRI = getTargetMachine().getRegisterInfo();
const ARMBaseRegisterInfo *ARI = static_cast<const ARMBaseRegisterInfo*>(TRI);
if (isThisReturn) {
// For 'this' returns, use the R0-preserving mask if applicable
Mask = ARI->getThisReturnPreservedMask(CallConv);
if (!Mask) {
// Set isThisReturn to false if the calling convention is not one that
// allows 'returned' to be modeled in this way, so LowerCallResult does
// not try to pass 'this' straight through
isThisReturn = false;
Mask = ARI->getCallPreservedMask(CallConv);
}
} else
Mask = ARI->getCallPreservedMask(CallConv);
}
} else
Mask = ARI->getCallPreservedMask(CallConv);
assert(Mask && "Missing call preserved mask for calling convention");
Ops.push_back(DAG.getRegisterMask(Mask));
assert(Mask && "Missing call preserved mask for calling convention");
Ops.push_back(DAG.getRegisterMask(Mask));
}
if (InFlag.getNode())
Ops.push_back(InFlag);

35
test/CodeGen/ARM/ifconv-regmask.ll Normal file
View File

@ -0,0 +1,35 @@
; RUN: llc < %s -mtriple=thumbv7s-apple-ios6.0.0 -verify-machineinstrs
%union.opcode = type { i32 }
@opcode = external global %union.opcode, align 4
; Function Attrs: nounwind ssp
define i32 @sfu() {
entry:
%bf.load = load i32* getelementptr inbounds (%union.opcode* @opcode, i32 0, i32 0), align 4
%bf.lshr = lshr i32 %bf.load, 26
%bf.clear = and i32 %bf.lshr, 7
switch i32 %bf.clear, label %return [
i32 0, label %sw.bb
i32 1, label %sw.bb1
]
sw.bb: ; preds = %entry
%call = tail call i32 @func0()
br label %return
sw.bb1: ; preds = %entry
%call2 = tail call i32 @func1()
br label %return
return: ; preds = %sw.bb1, %sw.bb, %entry
%retval.0 = phi i32 [ %call2, %sw.bb1 ], [ %call, %sw.bb ], [ -1, %entry ]
ret i32 %retval.0
}
; Function Attrs: nounwind ssp
declare i32 @func0()
; Function Attrs: nounwind ssp
declare i32 @func1()