Evan Cheng c5f50f7322 SimplifyCFG has stopped duplicating returns into predecessors to canonicalize IR ... to have single return block (at least getting there) for optimizations. This is general goodness but it would prevent some tailcall optimizations. One specific case is code like this: int f1(void); int f2(void); int f3(void); int f4(void); int f5(void); int f6(void); int foo(int x) { switch(x) { case 1: return f1(); case 2: return f2(); case 3: return f3(); case 4: return f4(); case 5: return f5(); case 6: return f6(); } } => LBB0_2: ## %sw.bb callq _f1 popq %rbp ret LBB0_3: ## %sw.bb1 callq _f2 popq %rbp ret LBB0_4: ## %sw.bb3 callq _f3 popq %rbp ret This patch teaches codegenprep to duplicate returns when the return value is a phi and where the phi operands are produced by tail calls followed by an unconditional branch: sw.bb7: ; preds = %entry %call8 = tail call i32 @f5() nounwind br label %return sw.bb9: ; preds = %entry %call10 = tail call i32 @f6() nounwind br label %return return: %retval.0 = phi i32 [ %call10, %sw.bb9 ], [ %call8, %sw.bb7 ], ... [ 0, %entry ] ret i32 %retval.0 This allows codegen to generate better code like this: LBB0_2: ## %sw.bb jmp _f1 ## TAILCALL LBB0_3: ## %sw.bb1 jmp _f2 ## TAILCALL LBB0_4: ## %sw.bb3 jmp _f3 ## TAILCALL rdar://9147433 llvm-svn: 127953		2011-03-19 17:17:39 +00:00
..
Analysis	Propagate SCEV no-wrap flags whenever possible.	2011-03-15 00:37:00 +00:00
Archive
Assembler	Reapply: Add type output to llvm-dis annotations. Patch by Yuri!	2011-03-17 19:50:04 +00:00
Bindings/Ocaml	XFAIL vg_leak the new test as the rest.	2010-12-23 21:22:09 +00:00
Bitcode
BugPoint
CodeGen	SimplifyCFG has stopped duplicating returns into predecessors to canonicalize IR	2011-03-19 17:17:39 +00:00
DebugInfo	Remove obsolete tests.	2011-02-24 19:09:52 +00:00
ExecutionEngine
Feature
FrontendAda	Testcase for dragonegg commit 124128.	2011-01-24 18:04:33 +00:00
FrontendC	Disable test to unbreak Linux. Radar 9156771.	2011-03-19 03:56:38 +00:00
FrontendC++	remove a small scattering of basically pointless tests. These are	2011-02-09 16:41:31 +00:00
FrontendFortran
FrontendObjC	Testcase for r127301.	2011-03-09 01:05:00 +00:00
FrontendObjC++
Integer
lib
Linker	Correctly merge available_externally and regular definitions when they have	2011-02-01 05:33:52 +00:00
LLVMC
MC	Fixed an assert by the ARM disassembler for LDRD_PRE/POST.	2011-03-19 01:16:20 +00:00
Object	Revert "Object: Renable the tests now that none of the build bots complain about aliasing."	2011-01-21 06:27:04 +00:00
Other
Scripts	Print all 64bits for st_value and st_size. Adjust tests accordingly.	2010-12-20 20:49:43 +00:00
TableGen	Rename lisp-like functions as suggested by Gabor Greif as loooong time	2011-01-07 17:05:37 +00:00
Transforms	Avoid creating canonical induction variables for non-native types.	2011-03-18 16:50:32 +00:00
Unit
Verifier
CMakeLists.txt	Put targets on folders, if the IDE supports the feature.	2011-02-20 22:06:10 +00:00
lit.cfg	test/lit.cfg: Add PATHEXT to 'substitution', to recognize tools on Windows hosts. Thanks to Danil Malyshev!	2011-02-24 12:34:34 +00:00
lit.site.cfg.in	CMake: Add the new option LLVM_LIT_TOOLS_DIR. It can specify "Path to GnuWin32 tools".	2011-02-09 04:18:58 +00:00
Makefile	Reapply r127073(partially): Introduce $(ECHOPATH) to print DOSish path string on MSYS bash for alternative of $(ECHO).	2011-03-08 12:25:10 +00:00
Makefile.tests
site.exp.in
TestRunner.sh