[PATCH] Do not insert a tail call when returning multiple values on X86
Keno Fischer
kfischer at college.harvard.edu
Wed Aug 20 12:09:54 PDT 2014
Closed by commit rL216117 (authored by kfischer).
REPOSITORY
rL LLVM
http://reviews.llvm.org/D4968
Files:
llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
llvm/trunk/test/CodeGen/X86/tailcall-multiret.ll
Index: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
===================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
@@ -2052,6 +2052,13 @@
UI != UE; ++UI) {
if (UI->getOpcode() != X86ISD::RET_FLAG)
return false;
+ // If we are returning more than one value, we can definitely
+ // not make a tail call see PR19530
+ if (UI->getNumOperands() > 4)
+ return false;
+ if (UI->getNumOperands() == 4 &&
+ UI->getOperand(UI->getNumOperands()-1).getValueType() != MVT::Glue)
+ return false;
HasRet = true;
}
Index: llvm/trunk/test/CodeGen/X86/tailcall-multiret.ll
===================================================================
--- llvm/trunk/test/CodeGen/X86/tailcall-multiret.ll
+++ llvm/trunk/test/CodeGen/X86/tailcall-multiret.ll
@@ -0,0 +1,16 @@
+; RUN: llc < %s -mtriple=x86_64-linux-gnu -mcpu=core2 | FileCheck %s
+; See PR19530
+declare double @llvm.powi.f64(double %Val, i32 %power)
+define <3 x double> @julia_foo17589(i32 %arg) {
+ %tmp1 = call double @llvm.powi.f64(double 1.000000e+00, i32 %arg)
+; CHECK: callq __powidf2
+ %tmp2 = insertelement <3 x double> undef, double %tmp1, i32 0
+ %tmp3 = call double @llvm.powi.f64(double 2.000000e+00, i32 %arg)
+; CHECK: callq __powidf2
+ %tmp4 = insertelement <3 x double> %tmp2, double %tmp3, i32 1
+ %tmp5 = call double @llvm.powi.f64(double 3.000000e+00, i32 %arg)
+; CHECK: callq __powidf2
+ %tmp6 = insertelement <3 x double> %tmp4, double %tmp5, i32 2
+; CHECK-NOT: TAILCALL
+ ret <3 x double> %tmp6
+}
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