llvm-project/llvm/test/Transforms/GVN/2008-07-02-Unreachable.ll

; RUN: opt < %s -basicaa -gvn -S | grep "ret i8 [%]tmp3"
; PR2503

@g_3 = external global i8		; <i8*> [#uses=2]

define i8 @func_1(i32 %x, i32 %y) nounwind  {
entry:
  %A = alloca i8
    %cmp = icmp eq i32 %x, %y
	br i1 %cmp, label %ifelse, label %ifthen

ifthen:		; preds = %entry
	br label %ifend

ifelse:		; preds = %entry
	%tmp3 = load i8* @g_3		; <i8> [#uses=0]
        store i8 %tmp3, i8* %A
	br label %afterfor

forcond:		; preds = %forinc
	br i1 false, label %afterfor, label %forbody

forbody:		; preds = %forcond
	br label %forinc

forinc:		; preds = %forbody
	br label %forcond

afterfor:		; preds = %forcond, %forcond.thread
	%tmp10 = load i8* @g_3		; <i8> [#uses=0]
	ret i8 %tmp10

ifend:		; preds = %afterfor, %ifthen
	ret i8 0
}
Convert all tests using TCL-style quoting to use shell-style quoting. This was done through the aid of a terrible Perl creation. I will not paste any of the horrors here. Suffice to say, it require multiple staged rounds of replacements, state carried between, and a few nested-construct-parsing hacks that I'm not proud of. It happens, by luck, to be able to deal with all the TCL-quoting patterns in evidence in the LLVM test suite. If anyone is maintaining large out-of-tree test trees, feel free to poke me and I'll send you the steps I used to convert things, as well as answer any painful questions etc. IRC works best for this type of thing I find. Once converted, switch the LLVM lit config to use ShTests the same as Clang. In addition to being able to delete large amounts of Python code from 'lit', this will also simplify the entire test suite and some of lit's architecture. Finally, the test suite runs 33% faster on Linux now. ;] For my 16-hardware-thread (2x 4-core xeon e5520): 36s -> 24s llvm-svn: 159525 2012-07-02 20:47:22 +08:00			`; RUN: opt < %s -basicaa -gvn -S \| grep "ret i8 [%]tmp3"`
A better fix for PR2503 that doesn't pessimize GVN in the presence of unreachable blocks. llvm-svn: 53032 2008-07-03 01:20:16 +08:00			`; PR2503`
don't require GVN to work on dead values, just make the test return the loaded value. llvm-svn: 60252 2008-11-30 05:21:48 +08:00
A better fix for PR2503 that doesn't pessimize GVN in the presence of unreachable blocks. llvm-svn: 53032 2008-07-03 01:20:16 +08:00			`@g_3 = external global i8 ; <i8*> [#uses=2]`

Fix PR17952. The symptom is that an assertion is triggered. The assertion was added by me to detect the situation when value is propagated from dead blocks. (We can certainly get rid of assertion; it is safe to do so, because propagating value from dead block to alive join node is certainly ok.) The root cause of this bug is : edge-splitting is conducted on the fly, the edge being split could be a dead edge, therefore the block that split the critial edge needs to be flagged "dead" as well. There are 3 ways to fix this bug: 1) Get rid of the assertion as I mentioned eariler 2) When an dead edge is split, flag the inserted block "dead". 3) proactively split the critical edges connecting dead and live blocks when new dead blocks are revealed. This fix go for 3) with additional 2 LOC. Testing case was added by Rafael the other day. llvm-svn: 194424 2013-11-12 06:00:23 +08:00			`define i8 @func_1(i32 %x, i32 %y) nounwind {`
A better fix for PR2503 that doesn't pessimize GVN in the presence of unreachable blocks. llvm-svn: 53032 2008-07-03 01:20:16 +08:00			`entry:`
remove a trivial test, make some other tests less trivial. llvm-svn: 131846 2011-05-22 15:02:43 +08:00			`%A = alloca i8`
Fix PR17952. The symptom is that an assertion is triggered. The assertion was added by me to detect the situation when value is propagated from dead blocks. (We can certainly get rid of assertion; it is safe to do so, because propagating value from dead block to alive join node is certainly ok.) The root cause of this bug is : edge-splitting is conducted on the fly, the edge being split could be a dead edge, therefore the block that split the critial edge needs to be flagged "dead" as well. There are 3 ways to fix this bug: 1) Get rid of the assertion as I mentioned eariler 2) When an dead edge is split, flag the inserted block "dead". 3) proactively split the critical edges connecting dead and live blocks when new dead blocks are revealed. This fix go for 3) with additional 2 LOC. Testing case was added by Rafael the other day. llvm-svn: 194424 2013-11-12 06:00:23 +08:00			`%cmp = icmp eq i32 %x, %y`
			`br i1 %cmp, label %ifelse, label %ifthen`
A better fix for PR2503 that doesn't pessimize GVN in the presence of unreachable blocks. llvm-svn: 53032 2008-07-03 01:20:16 +08:00
			`ifthen: ; preds = %entry`
			`br label %ifend`

			`ifelse: ; preds = %entry`
			`%tmp3 = load i8* @g_3 ; <i8> [#uses=0]`
remove a trivial test, make some other tests less trivial. llvm-svn: 131846 2011-05-22 15:02:43 +08:00			`store i8 %tmp3, i8* %A`
A better fix for PR2503 that doesn't pessimize GVN in the presence of unreachable blocks. llvm-svn: 53032 2008-07-03 01:20:16 +08:00			`br label %afterfor`

			`forcond: ; preds = %forinc`
			`br i1 false, label %afterfor, label %forbody`

			`forbody: ; preds = %forcond`
			`br label %forinc`

			`forinc: ; preds = %forbody`
			`br label %forcond`

			`afterfor: ; preds = %forcond, %forcond.thread`
			`%tmp10 = load i8* @g_3 ; <i8> [#uses=0]`
don't require GVN to work on dead values, just make the test return the loaded value. llvm-svn: 60252 2008-11-30 05:21:48 +08:00			`ret i8 %tmp10`
A better fix for PR2503 that doesn't pessimize GVN in the presence of unreachable blocks. llvm-svn: 53032 2008-07-03 01:20:16 +08:00
			`ifend: ; preds = %afterfor, %ifthen`
don't require GVN to work on dead values, just make the test return the loaded value. llvm-svn: 60252 2008-11-30 05:21:48 +08:00			`ret i8 0`
A better fix for PR2503 that doesn't pessimize GVN in the presence of unreachable blocks. llvm-svn: 53032 2008-07-03 01:20:16 +08:00			`}`