diff options
| author | Hal Finkel <hfinkel@anl.gov> | 2013-07-01 19:34:59 +0000 |
|---|---|---|
| committer | Hal Finkel <hfinkel@anl.gov> | 2013-07-01 19:34:59 +0000 |
| commit | b5f7b0f9780cd1bc6f948b194adfc57176d41711 (patch) | |
| tree | 8e420c6c590a8bc8cff2845039b59a5209cbf4ec | |
| parent | 6711fc28a41c05e1c8398393c7794c41b2ee0202 (diff) | |
| download | external_llvm-b5f7b0f9780cd1bc6f948b194adfc57176d41711.zip external_llvm-b5f7b0f9780cd1bc6f948b194adfc57176d41711.tar.gz external_llvm-b5f7b0f9780cd1bc6f948b194adfc57176d41711.tar.bz2 | |
Don't form PPC CTR loops for over-sized exit counts
Although you can't generate this from C on PPC64, if you have a loop using a
64-bit counter on PPC32 then you can't form a CTR-based loop for it. This had
been cauing the PPCCTRLoops pass to assert.
Thanks to Joerg Sonnenberger for providing a test case!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185361 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/Target/PowerPC/PPCCTRLoops.cpp | 3 | ||||
| -rw-r--r-- | test/CodeGen/PowerPC/ctrloop-large-ec.ll | 23 |
2 files changed, 26 insertions, 0 deletions
diff --git a/lib/Target/PowerPC/PPCCTRLoops.cpp b/lib/Target/PowerPC/PPCCTRLoops.cpp index 08247c2..bfc9495 100644 --- a/lib/Target/PowerPC/PPCCTRLoops.cpp +++ b/lib/Target/PowerPC/PPCCTRLoops.cpp @@ -415,6 +415,9 @@ bool PPCCTRLoops::convertToCTRLoop(Loop *L) { } else if (!SE->isLoopInvariant(EC, L)) continue; + if (SE->getTypeSizeInBits(EC->getType()) > (TT.isArch64Bit() ? 64 : 32)) + continue; + // We now have a loop-invariant count of loop iterations (which is not the // constant zero) for which we know that this loop will not exit via this // exisiting block. diff --git a/test/CodeGen/PowerPC/ctrloop-large-ec.ll b/test/CodeGen/PowerPC/ctrloop-large-ec.ll new file mode 100644 index 0000000..c18bdab --- /dev/null +++ b/test/CodeGen/PowerPC/ctrloop-large-ec.ll @@ -0,0 +1,23 @@ +; RUN: llc -mcpu=ppc32 < %s +target datalayout = "E-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v128:128:128-n32" +target triple = "powerpc-unknown-linux-gnu" + +define void @fn1() { +entry: + br i1 undef, label %for.end, label %for.body + +for.body: ; preds = %for.body, %entry + %inc3 = phi i64 [ %inc, %for.body ], [ undef, %entry ] + %inc = add nsw i64 %inc3, 1 + %tobool = icmp eq i64 %inc, 0 + br i1 %tobool, label %for.end, label %for.body + +for.end: ; preds = %for.body, %entry + ret void +} + +; On PPC32, CTR is also 32 bits, and so cannot hold a 64-bit count. +; CHECK: @fn1 +; CHECK-NOT: mtctr +; CHECK: blr + |