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authorHal Finkel <hfinkel@anl.gov>2013-08-19 23:35:24 +0000
committerHal Finkel <hfinkel@anl.gov>2013-08-19 23:35:24 +0000
commit30cbccb029b01738202bd04341b1cbf68a7814c9 (patch)
treeab75a4420b789d4acb234ac64e049193e5cf6753
parentff9fa05905be716435460b5f6d32689041bf895b (diff)
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Don't form PPC CTR-based loops around a copysignl call
copysign/copysignf never become function calls (because the SDAG expansion code does not lower to the corresponding function call, but rather directly implements the associated logic), but copysignl almost always is lowered into a call to the requested libm functon (and, thus, might clobber CTR). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188727 91177308-0d34-0410-b5e6-96231b3b80d8
-rw-r--r--lib/Target/PowerPC/PPCCTRLoops.cpp3
-rw-r--r--test/CodeGen/PowerPC/ctrloop-cpsgn.ll28
2 files changed, 30 insertions, 1 deletions
diff --git a/lib/Target/PowerPC/PPCCTRLoops.cpp b/lib/Target/PowerPC/PPCCTRLoops.cpp
index 05dad8a..d9f1323 100644
--- a/lib/Target/PowerPC/PPCCTRLoops.cpp
+++ b/lib/Target/PowerPC/PPCCTRLoops.cpp
@@ -284,8 +284,9 @@ bool PPCCTRLoops::mightUseCTR(const Triple &TT, BasicBlock *BB) {
default: return true;
case LibFunc::copysign:
case LibFunc::copysignf:
- case LibFunc::copysignl:
continue; // ISD::FCOPYSIGN is never a library call.
+ case LibFunc::copysignl:
+ return true;
case LibFunc::fabs:
case LibFunc::fabsf:
case LibFunc::fabsl:
diff --git a/test/CodeGen/PowerPC/ctrloop-cpsgn.ll b/test/CodeGen/PowerPC/ctrloop-cpsgn.ll
new file mode 100644
index 0000000..2f04409
--- /dev/null
+++ b/test/CodeGen/PowerPC/ctrloop-cpsgn.ll
@@ -0,0 +1,28 @@
+; RUN: llc < %s -mcpu=ppc | FileCheck %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 ppc_fp128 @foo(ppc_fp128* nocapture %n, ppc_fp128 %d) nounwind readonly {
+entry:
+ br label %for.body
+
+for.body: ; preds = %for.body, %entry
+ %i.06 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
+ %x.05 = phi ppc_fp128 [ %d, %entry ], [ %conv, %for.body ]
+ %arrayidx = getelementptr inbounds ppc_fp128* %n, i32 %i.06
+ %0 = load ppc_fp128* %arrayidx, align 8
+ %conv = tail call ppc_fp128 @copysignl(ppc_fp128 %x.05, ppc_fp128 %d) nounwind readonly
+ %inc = add nsw i32 %i.06, 1
+ %exitcond = icmp eq i32 %inc, 2048
+ br i1 %exitcond, label %for.end, label %for.body
+
+for.end: ; preds = %for.body
+ ret ppc_fp128 %conv
+}
+
+declare ppc_fp128 @copysignl(ppc_fp128, ppc_fp128) #0
+
+; CHECK: @foo
+; CHECK-NOT: mtctr
+