[llvm-commits] [llvm] r94873 - in /llvm/trunk: lib/Target/X86/X86ISelLowering.cpp test/CodeGen/X86/2009-11-04-SubregCoalescingBug.ll test/CodeGen/X86/tailcall2.ll
Evan Cheng
evan.cheng at apple.com
Fri Jan 29 17:22:00 PST 2010
Author: evancheng
Date: Fri Jan 29 19:22:00 2010
New Revision: 94873
URL: http://llvm.org/viewvc/llvm-project?rev=94873&view=rev
Log:
Allow more tailcall optimization: calls with inputs that are all passed in registers.
Modified:
llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
llvm/trunk/test/CodeGen/X86/2009-11-04-SubregCoalescingBug.ll
llvm/trunk/test/CodeGen/X86/tailcall2.ll
Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=94873&r1=94872&r2=94873&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Fri Jan 29 19:22:00 2010
@@ -2258,9 +2258,18 @@
return true;
// Look for obvious safe cases to perform tail call optimization.
- // For now, only consider callees which take no arguments.
- if (!Outs.empty())
- return false;
+ // If the callee takes no arguments then go on to check the results of the
+ // call.
+ if (!Outs.empty()) {
+ // Check if stack adjustment is needed. For now, do not do this if any
+ // argument is passed on the stack.
+ SmallVector<CCValAssign, 16> ArgLocs;
+ CCState CCInfo(CalleeCC, isVarArg, getTargetMachine(),
+ ArgLocs, *DAG.getContext());
+ CCInfo.AnalyzeCallOperands(Outs, CCAssignFnForNode(CalleeCC));
+ if (CCInfo.getNextStackOffset())
+ return false;
+ }
// If the caller does not return a value, then this is obviously safe.
// This is one case where it's safe to perform this optimization even
Modified: llvm/trunk/test/CodeGen/X86/2009-11-04-SubregCoalescingBug.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/2009-11-04-SubregCoalescingBug.ll?rev=94873&r1=94872&r2=94873&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/2009-11-04-SubregCoalescingBug.ll (original)
+++ llvm/trunk/test/CodeGen/X86/2009-11-04-SubregCoalescingBug.ll Fri Jan 29 19:22:00 2010
@@ -5,7 +5,7 @@
entry:
; CHECK: leal 15(%rsi), %edi
; CHECK-NOT: movl
-; CHECK: callq _foo
+; CHECK: jmp _foo
%0 = add i32 %a, 15 ; <i32> [#uses=1]
%1 = zext i32 %0 to i64 ; <i64> [#uses=1]
tail call void @foo(i64 %1) nounwind
Modified: llvm/trunk/test/CodeGen/X86/tailcall2.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/tailcall2.ll?rev=94873&r1=94872&r2=94873&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/tailcall2.ll (original)
+++ llvm/trunk/test/CodeGen/X86/tailcall2.ll Fri Jan 29 19:22:00 2010
@@ -1,10 +1,13 @@
-; RUN: llc < %s -march=x86 -asm-verbose=false | FileCheck %s
-; RUN: llc < %s -march=x86-64 -asm-verbose=false | FileCheck %s
+; RUN: llc < %s -march=x86 -asm-verbose=false | FileCheck %s -check-prefix=32
+; RUN: llc < %s -march=x86-64 -asm-verbose=false | FileCheck %s -check-prefix=64
define void @t1(i32 %x) nounwind ssp {
entry:
-; CHECK: t1:
-; CHECK: jmp {{_?}}foo
+; 32: t1:
+; 32: jmp {{_?}}foo
+
+; 64: t1:
+; 64: jmp {{_?}}foo
tail call void @foo() nounwind
ret void
}
@@ -13,8 +16,11 @@
define void @t2() nounwind ssp {
entry:
-; CHECK: t2:
-; CHECK: jmp {{_?}}foo2
+; 32: t2:
+; 32: jmp {{_?}}foo2
+
+; 64: t2:
+; 64: jmp {{_?}}foo2
%0 = tail call i32 @foo2() nounwind
ret void
}
@@ -23,10 +29,39 @@
define void @t3() nounwind ssp {
entry:
-; CHECK: t3:
-; CHECK: jmp {{_?}}foo3
+; 32: t3:
+; 32: jmp {{_?}}foo3
+
+; 64: t3:
+; 64: jmp {{_?}}foo3
%0 = tail call i32 @foo3() nounwind
ret void
}
declare i32 @foo3()
+
+define void @t4(void (i32)* nocapture %x) nounwind ssp {
+entry:
+; 32: t4:
+; 32: call *
+; FIXME: gcc can generate a tailcall for this. But it's tricky.
+
+; 64: t4:
+; 64-NOT: call
+; 64: jmpq *
+ tail call void %x(i32 0) nounwind
+ ret void
+}
+
+define void @t5(void ()* nocapture %x) nounwind ssp {
+entry:
+; 32: t5:
+; 32-NOT: call
+; 32: jmpl *
+
+; 64: t5:
+; 64-NOT: call
+; 64: jmpq *
+ tail call void %x() nounwind
+ ret void
+}
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