diff options
| author | Jakob Stoklund Olesen <stoklund@2pi.dk> | 2012-06-19 21:14:34 +0000 |
|---|---|---|
| committer | Jakob Stoklund Olesen <stoklund@2pi.dk> | 2012-06-19 21:14:34 +0000 |
| commit | 7164288c3eb52e20454fc757440f867f04eb13a4 (patch) | |
| tree | e2599c6d8ee747086bbc76dd5a2dff8ba5339ae9 /test/CodeGen/PowerPC/coalesce-ext.ll | |
| parent | d8d0279c007e70c325b4ac9d9893b31ee5f21085 (diff) | |
Implement PPCInstrInfo::isCoalescableExtInstr().
The PPC::EXTSW instruction preserves the low 32 bits of its input, just
like some of the x86 instructions. Use it to reduce register pressure
when the low 32 bits have multiple uses.
This requires a small change to PeepholeOptimizer since EXTSW takes a
64-bit input register.
This is related to PR5997.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158743 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test/CodeGen/PowerPC/coalesce-ext.ll')
| -rw-r--r-- | test/CodeGen/PowerPC/coalesce-ext.ll | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/test/CodeGen/PowerPC/coalesce-ext.ll b/test/CodeGen/PowerPC/coalesce-ext.ll new file mode 100644 index 00000000000..08a2cc773fd --- /dev/null +++ b/test/CodeGen/PowerPC/coalesce-ext.ll @@ -0,0 +1,17 @@ +; RUN: llc -march=ppc64 < %s | FileCheck %s +; Check that the peephole optimizer knows about sext and zext instructions. +; CHECK: test1sext +define i32 @test1sext(i64 %A, i64 %B, i32* %P, i64 *%P2) nounwind { + %C = add i64 %A, %B + ; CHECK: add [[SUM:r[0-9]+]], r3, r4 + %D = trunc i64 %C to i32 + %E = shl i64 %C, 32 + %F = ashr i64 %E, 32 + ; CHECK: extsw [[EXT:r[0-9]+]], [[SUM]] + store volatile i64 %F, i64 *%P2 + ; CHECK: std [[EXT]] + store volatile i32 %D, i32* %P + ; Reuse low bits of extended register, don't extend live range of SUM. + ; CHECK: stw [[EXT]] + ret i32 %D +} |