From 5f587c59a53f4daf44fc4f0679347bd00773885f Mon Sep 17 00:00:00 2001 From: Hal Finkel Date: Thu, 16 May 2013 19:58:38 +0000 Subject: Create an new preheader in PPCCTRLoops to avoid counter register clobbers Some IR-level instructions (such as FP <-> i64 conversions) are not chained w.r.t. the mtctr intrinsic and yet may become function calls that clobber the counter register. At the selection-DAG level, these might be reordered with the mtctr intrinsic causing miscompiles. To avoid this situation, if an existing preheader has instructions that might use the counter register, create a new preheader for the mtctr intrinsic. This extra block will be remerged with the old preheader at the MI level, but will prevent unwanted reordering at the selection-DAG level. llvm-svn: 182045 --- llvm/test/CodeGen/PowerPC/ctrloop-fp64.ll | 32 +++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) (limited to 'llvm/test/CodeGen/PowerPC/ctrloop-fp64.ll') diff --git a/llvm/test/CodeGen/PowerPC/ctrloop-fp64.ll b/llvm/test/CodeGen/PowerPC/ctrloop-fp64.ll index 78974248da5..313177c91e6 100644 --- a/llvm/test/CodeGen/PowerPC/ctrloop-fp64.ll +++ b/llvm/test/CodeGen/PowerPC/ctrloop-fp64.ll @@ -26,3 +26,35 @@ for.end: ; preds = %for.body ; CHECK: @foo ; CHECK-NOT: mtctr +@init_value = global double 1.000000e+00, align 8 +@data64 = global [8000 x i64] zeroinitializer, align 8 + +define i32 @main(i32 %argc, i8** nocapture %argv) { +entry: + %0 = load double* @init_value, align 8 + %conv = fptosi double %0 to i64 + %broadcast.splatinsert.i = insertelement <2 x i64> undef, i64 %conv, i32 0 + %broadcast.splat.i = shufflevector <2 x i64> %broadcast.splatinsert.i, <2 x i64> undef, <2 x i32> zeroinitializer + br label %vector.body.i + +vector.body.i: ; preds = %vector.body.i, %entry + %index.i = phi i32 [ 0, %entry ], [ %index.next.i, %vector.body.i ] + %next.gep.i = getelementptr [8000 x i64]* @data64, i32 0, i32 %index.i + %1 = bitcast i64* %next.gep.i to <2 x i64>* + store <2 x i64> %broadcast.splat.i, <2 x i64>* %1, align 8 + %next.gep.sum24.i = or i32 %index.i, 2 + %2 = getelementptr [8000 x i64]* @data64, i32 0, i32 %next.gep.sum24.i + %3 = bitcast i64* %2 to <2 x i64>* + store <2 x i64> %broadcast.splat.i, <2 x i64>* %3, align 8 + %index.next.i = add i32 %index.i, 4 + %4 = icmp eq i32 %index.next.i, 8000 + br i1 %4, label %_Z4fillIPxxEvT_S1_T0_.exit, label %vector.body.i + +_Z4fillIPxxEvT_S1_T0_.exit: ; preds = %vector.body.i + ret i32 0 +} + +; CHECK: @main +; CHECK: __fixdfdi +; CHECK: mtctr + -- cgit v1.2.3