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| author | Bob Wilson <bob.wilson@apple.com> | 2010-02-10 22:58:57 +0000 |
|---|---|---|
| committer | Bob Wilson <bob.wilson@apple.com> | 2010-02-10 22:58:57 +0000 |
| commit | 5e2b05a71e81b28712b77419f68657462494e103 (patch) | |
| tree | 8029ae1969d5fb607781fba7e98b005022475af7 | |
| parent | b8ff934e94637462901ebd1c849aeaf71350dacc (diff) | |
| download | external_llvm-5e2b05a71e81b28712b77419f68657462494e103.zip external_llvm-5e2b05a71e81b28712b77419f68657462494e103.tar.gz external_llvm-5e2b05a71e81b28712b77419f68657462494e103.tar.bz2 | |
Delete dead PHI machine instructions. These can be created due to type
legalization even when the IR-level optimizer has removed dead phis, such
as when the high half of an i64 value is unused on a 32-bit target.
I had to adjust a few test cases that had dead phis.
This is a partial fix for Radar 7627077.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95816 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/CodeGen/DeadMachineInstructionElim.cpp | 2 | ||||
| -rw-r--r-- | test/CodeGen/ARM/remat.ll | 6 | ||||
| -rw-r--r-- | test/CodeGen/X86/2007-10-05-3AddrConvert.ll | 4 |
3 files changed, 7 insertions, 5 deletions
diff --git a/lib/CodeGen/DeadMachineInstructionElim.cpp b/lib/CodeGen/DeadMachineInstructionElim.cpp index b0cb24d..6e01e59 100644 --- a/lib/CodeGen/DeadMachineInstructionElim.cpp +++ b/lib/CodeGen/DeadMachineInstructionElim.cpp @@ -55,7 +55,7 @@ FunctionPass *llvm::createDeadMachineInstructionElimPass() { bool DeadMachineInstructionElim::isDead(const MachineInstr *MI) const { // Don't delete instructions with side effects. bool SawStore = false; - if (!MI->isSafeToMove(TII, SawStore, 0)) + if (!MI->isSafeToMove(TII, SawStore, 0) && !MI->isPHI()) return false; // Examine each operand. diff --git a/test/CodeGen/ARM/remat.ll b/test/CodeGen/ARM/remat.ll index 367f782..92c1cf1 100644 --- a/test/CodeGen/ARM/remat.ll +++ b/test/CodeGen/ARM/remat.ll @@ -32,16 +32,16 @@ bb.i35: ; preds = %bb142 br label %phi1.exit phi1.exit: ; preds = %bb.i35, %bb142 - %.pn = phi double [ %6, %bb.i35 ], [ 0.000000e+00, %bb142 ] ; <double> [#uses=0] + %.pn = phi double [ %6, %bb.i35 ], [ 0.000000e+00, %bb142 ] ; <double> [#uses=1] %9 = phi double [ %8, %bb.i35 ], [ 0.000000e+00, %bb142 ] ; <double> [#uses=1] - %10 = fmul double undef, %9 ; <double> [#uses=0] + %10 = fmul double %.pn, %9 ; <double> [#uses=1] br i1 %14, label %phi0.exit, label %bb.i bb.i: ; preds = %phi1.exit unreachable phi0.exit: ; preds = %phi1.exit - %11 = fsub double %4, undef ; <double> [#uses=1] + %11 = fsub double %4, %10 ; <double> [#uses=1] %12 = fadd double 0.000000e+00, %11 ; <double> [#uses=1] store double %12, double* undef, align 4 br label %bb142 diff --git a/test/CodeGen/X86/2007-10-05-3AddrConvert.ll b/test/CodeGen/X86/2007-10-05-3AddrConvert.ll index 67323e8..2c2706d 100644 --- a/test/CodeGen/X86/2007-10-05-3AddrConvert.ll +++ b/test/CodeGen/X86/2007-10-05-3AddrConvert.ll @@ -36,7 +36,9 @@ bb.i6.i: ; preds = %bb.i6.i, %stepsystem.exit.i bb107.i.i: ; preds = %bb107.i.i, %bb.i6.i %q_addr.0.i.i.in = phi %struct.bnode** [ null, %bb107.i.i ], [ %4, %bb.i6.i ] ; <%struct.bnode**> [#uses=1] - %q_addr.0.i.i = load %struct.bnode** %q_addr.0.i.i.in ; <%struct.bnode*> [#uses=0] + %q_addr.0.i.i = load %struct.bnode** %q_addr.0.i.i.in ; <%struct.bnode*> [#uses=1] + %q_addr.1 = getelementptr %struct.anon* %0, i32 0, i32 4, i32 1 + store %struct.bnode* %q_addr.0.i.i, %struct.bnode** %q_addr.1, align 4 br label %bb107.i.i bb47.loopexit.i: ; preds = %bb32.i |