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author | Sean Fertile <sfertile@ca.ibm.com> | 2017-11-15 18:58:27 +0000 |
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committer | Sean Fertile <sfertile@ca.ibm.com> | 2017-11-15 18:58:27 +0000 |
commit | 0fe98240bda0f419861a73a8e7f67f6543ec1882 (patch) | |
tree | c61268054d28b0f83fa7ffe06c3d2e4d9608d415 /test/CodeGen/PowerPC | |
parent | 869a0096cdc99f6a396a3bad3965ae217c2f99ab (diff) |
[PowerPC] Implement mayBeEmittedAsTailCall for PPC
Implements TargetLowering callback 'mayBeEmittedAsTailCall' that enables
CodeGenPrepare to duplicate returns when they might enable a tail-call.
Differential Revision: https://reviews.llvm.org/D39777
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@318321 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test/CodeGen/PowerPC')
-rw-r--r-- | test/CodeGen/PowerPC/duplicate-returns-for-tailcall.ll | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/test/CodeGen/PowerPC/duplicate-returns-for-tailcall.ll b/test/CodeGen/PowerPC/duplicate-returns-for-tailcall.ll new file mode 100644 index 00000000000..520efd8106f --- /dev/null +++ b/test/CodeGen/PowerPC/duplicate-returns-for-tailcall.ll @@ -0,0 +1,63 @@ +; RUN: llc -verify-machineinstrs -mcpu=pwr8 -stop-after codegenprepare -mtriple=powerpc64le-unknown-gnu-linux < %s | FileCheck %s +; RUN: llc -verify-machineinstrs -mcpu=pwr8 -stop-after codegenprepare -mtriple=powerpc64-unknown-gnu-linux < %s | FileCheck %s + +; Function Attrs: noinline norecurse nounwind readnone +define hidden signext i32 @call1(i32 signext %a, i32 signext %b, i32 signext %c) local_unnamed_addr #0 { +entry: + %add = add nsw i32 %b, %a + %add1 = add nsw i32 %add, %c + ret i32 %add1 +} + +; Function Attrs: nounwind +define signext i32 @test(i32 signext %a, i32 signext %b, i32 signext %c) local_unnamed_addr #1 { +entry: + %cmp = icmp eq i32 %a, %b + br i1 %cmp, label %if.then, label %if.end + +if.then: ; preds = %entry + %call = tail call signext i32 @call1(i32 signext %a, i32 signext %b, i32 signext %c) + br label %return +; The return should get duplciated here to enable a tail-call opportunity. +; CHECK-LABEL: if.then: +; CHECK-NEXT: %[[T1:[a-zA-Z0-9]+]] = tail call signext i32 @call1 +; CHECK-NEXT: ret i32 %[[T1]] + +if.end: ; preds = %entry + %cmp1 = icmp slt i32 %a, %b + br i1 %cmp1, label %if.then2, label %if.end4 + +if.then2: ; preds = %if.end + %call3 = tail call signext i32 @call2(i32 signext %a, i32 signext %b, i32 signext %c) #3 + br label %return +; No duplication here since we cannot tail-call an external function anyway. +; CHECK-LABEL: if.then2: +; CHECK-NEXT: tail call signext i32 @call2 +; CHECK-NEXT: br + +if.end4: ; preds = %if.end + %cmp5 = icmp sgt i32 %b, %c + br i1 %cmp5, label %if.then6, label %return + +if.then6: ; preds = %if.end4 + %call7 = tail call fastcc signext i32 @call3(i32 signext %a, i32 signext %b, i32 signext %c) + br label %return +; No duplication here because the calling convention mismatch means we won't tail-call +; CHECK_LABEL: if.then13: +; CHECK: tail call fastcc signext i32 @call3 +; CHECK-NEXT: br + +return: ; preds = %if.end4, %if.then6, %if.then2, %if.then + %retval.0 = phi i32 [ %call, %if.then ], [ %call3, %if.then2 ], [ %call7, %if.then6 ], [ %c, %if.end4 ] + ret i32 %retval.0 +} + +declare signext i32 @call2(i32 signext, i32 signext, i32 signext) local_unnamed_addr #2 + +; Function Attrs: noinline norecurse nounwind readnone +define internal fastcc signext i32 @call3(i32 signext %a, i32 signext %b, i32 signext %c) unnamed_addr #0 { +entry: + %mul = mul nsw i32 %b, %a + %mul1 = mul nsw i32 %mul, %c + ret i32 %mul1 +} |