similar to: Debugging UNREACHABLE "Couldn't join subrange" in RegisterCoalescer (out-of-tree backend)

Displaying 20 results from an estimated 200 matches similar to: "Debugging UNREACHABLE "Couldn't join subrange" in RegisterCoalescer (out-of-tree backend)"

2012 Oct 25
2
[LLVMdev] RegisterCoalescing Pass seems to ignore part of CFG.
> > PHIElim and TwoAddress passes leave SSA form. > May be a missed something in your code but %vreg48 seems to be there > after PHI elimination. PHIElim tags those kind of registers as being > PHIJoin regs, updating LiveVariables pass, so the regcoalescer is aware > of them (some SSA info is still alive but the reg coalescer will > invalidate that information after
2012 Oct 25
0
[LLVMdev] RegisterCoalescing Pass seems to ignore part of CFG.
Hi Vincent, On 24/10/2012 23:26, Vincent Lejeune wrote: > Hi, > > I don't know if my llvm ir code is faulty, or if I spot a bug in the RegisterCoalescing Pass, so I'm posting my issue on the ML. Shader and print-before-all dump are given below. > > The interessing part is the vreg6/vreg48 reduction : before RegCoalescing, the machine code is : > > // BEFORE LOOP >
2012 Oct 25
0
[LLVMdev] RegisterCoalescing Pass seems to ignore part of CFG.
When examining the debug output of regalloc, it seems that joining 32bits reg also joins 128 parent reg. If I look at the : %vreg34<def> = COPY %vreg6:sel_y; R600_Reg32:%vreg34 R600_Reg128:%vreg6 instructions ; it gets joined to : 928B%vreg34<def> = COPY %vreg48:sel_y;  when vreg6 and vreg48 are joined. It's right. But joining the following copy 
2012 Oct 24
3
[LLVMdev] RegisterCoalescing Pass seems to ignore part of CFG.
Hi, I don't know if my llvm ir code is faulty, or if I spot a bug in the RegisterCoalescing Pass, so I'm posting my issue on the ML. Shader and print-before-all dump are given below. The interessing part is the vreg6/vreg48 reduction : before RegCoalescing, the machine code is : // BEFORE LOOP ... Some COPYs.... 400B%vreg47<def> = COPY %vreg2<kill>; R600_Reg32:%vreg47,%vreg2
2020 Apr 07
2
[ARM] Register pressure with -mthumb forces register reload before each call
If I'm understanding what's going on in this test correctly, what's happening is: * ARMTargetLowering::LowerCall prefers indirect calls when a function is called at least 3 times in minsize * In thumb 1 (without -fno-omit-frame-pointer) we have effectively only 3 callee-saved registers (r4-r6) * The function has three arguments, so those three plus the register we need to hold the
2015 Jan 17
2
[LLVMdev] Assertion: replaceAllUses of value with new value of different type! being thrown all of a sudden
Hello, I wonder if someone would know what is going on below. All of a sudden I’m getting this assertion thrown: Assertion failed: (New->getType() == getType() && "replaceAllUses of value with new value of different type!"), function replaceAllUsesWith, file /Users/meister/Development/externals-clasp/llvm36/lib/IR/Value.cpp, line 345. It’s happening when
2020 Mar 31
2
[ARM] Register pressure with -mthumb forces register reload before each call
Hi, Compiling attached test-case, which is reduced version of of uECC_shared_secret from tinycrypt library [1], with --target=arm-linux-gnueabi -march=armv6-m -Oz -S results in reloading of register holding function's address before every call to blx: ldr r3, .LCPI0_0 blx r3 mov r0, r6 mov r1, r5 mov r2, r4 ldr r3,
2012 Oct 25
3
[LLVMdev] RegisterCoalescing Pass seems to ignore part of CFG.
Hi Vincent, On 25/10/2012 18:14, Vincent Lejeune wrote: > When examining the debug output of regalloc, it seems that joining 32bits reg also joins 128 parent reg. > > If I look at the : > %vreg34<def> = COPY %vreg6:sel_y; R600_Reg32:%vreg34 R600_Reg128:%vreg6 > > instructions ; it gets joined to : > 928B%vreg34<def> = COPY %vreg48:sel_y; > > when vreg6 and
2016 Jun 08
2
Instruction Itineraries: question about operand latencies
I overrode getInstrLatency and did some printing to see what is available there. It looks like the registers are still virtual at that point when getInstrLatency is called - is that correct? (we needed to make some decisions based on actual registers that have been assigned since some registers are reserved as address space pointers and we could vary the latency based on which address space
2012 Oct 20
2
[LLVMdev] RegisterCoalescing pass crashes with ImplicitDef registers
Hi, below is an output of "llc -march=r600 -mcpu=cayman -print-before-all -debug-only=regalloc file.shader" command from llvm3.2svn. The register coalescing pass crashes when joining vreg12:sel_z with vreg13 registers, because it tries to access the interval liveness of vreg13... which is undefined. I don't know if it's a bug of the pass, or if my backend should do something
2012 Oct 25
0
[LLVMdev] RegisterCoalescing Pass seems to ignore part of CFG.
Thank for your help. You're right, merging vreg32 and vreg48 is perfectly fine, sorry I missed that. I "brute force" debuged by adding MachineFunction dump after each join, I think I found the issue : it's when vreg32 and vreg10 are merged. vreg10 only appears in BB#3, and the join only occurs in BB#3 apparently even if vreg32 lives in the 4 machine blocks After joining, there
2015 Jan 19
2
[LLVMdev] Assertion: replaceAllUses of value with new value of different type! being thrown all of a sudden
I forgot to mention this in my initial email. The build of LLVM that I was using was commit a0d5d7aed8e177cea381b3d054d80c212ece9f2c The date on the commit is: Date: Fri Sep 26 12:34:06 2014 Also: Today I grabbed the ToT llvm/clang/clang-extra-tools and I’m working on getting my code to be compatible with it. I can switch back and forth between the current ToT llvm and the old one. Thanks,
2012 Oct 26
1
[LLVMdev] RegisterCoalescing Pass seems to ignore part of CFG.
Vincent, File a bug report so you can get a fix for it. Ivan On 25/10/2012 23:01, Vincent Lejeune wrote: > Thank for your help. You're right, merging vreg32 and vreg48 is perfectly fine, sorry I missed that. > I "brute force" debuged by adding MachineFunction dump after each join, I think I found the issue : it's when vreg32 and vreg10 are merged. > vreg10 only
2020 Apr 15
4
[ARM] Register pressure with -mthumb forces register reload before each call
Hi, I have attached WIP patch for adding foldMemoryOperand to Thumb1InstrInfo. For the following case: void f(int x, int y, int z) { void bar(int, int, int); bar(x, y, z); bar(x, z, y); bar(y, x, z); bar(y, y, x); } it calls foldMemoryOperand twice, and thus converts two calls from blx to bl. callMI->dump() shows the function name "bar" correctly, however in generated
2015 Apr 09
3
[LLVMdev] Looking for advice on how to debug a problem with C++ style exception handling code that my compiler generates.
Hi, I’m looking for advice on how to debug a problem with my exception handling code. I’m asking a specific question here - but general advice on how to debug something like this would be greatly appreciated. Is there any way to get a list of landing pad clauses that are active at a particular point in a program? I'd like to get something like a backtrace but listing all active landing pad
2015 Apr 09
2
[LLVMdev] Looking for advice on how to debug a problem with C++ style exception handling code that my compiler generates.
Hi Christian, Andy's already covered the major points, but you could consider filing a bug at http://llvm.org/bugs too, especially if you've got a small test-case that demonstrates the issue. Exception handling hasn't been a priority in the past, but as more people adopt LLVM's JIT APIs I suspect it will get more attention, and bug reports will help us figure out what needs doing.
2015 Apr 12
2
[LLVMdev] Looking for advice on how to debug a problem with C++ style exception handling code that my compiler generates.
Hi Christian, > I don’t see anything in the Itanium ABI that says I need to call the function that throws an exception with “invoke” to get exception handling to work! AFAICT, it is the design of LLVM IR and its implementation. To catch the exceptions thrown by the callee functions, we should use the invoke instruction along with the landingpad instruction. If you are calling a function
2015 Apr 12
2
[LLVMdev] Looking for advice on how to debug a problem with C++ style exception handling code that my compiler generates.
Hi Christian, Thanks for your explanation. I know your situation now. I would suggest you to check the optimization pass used by the JIT compiler, especially IPO/PruneEH.cpp. It will try to add nounwind attribute to functions which will result in the problem you have mentioned earlier. Alternatively, as a workaround, try to add uwtable (function attribute) to the functions that are generated
2015 Apr 12
2
[LLVMdev] Looking for advice on how to debug a problem with C++ style exception handling code that my compiler generates.
Logan, I need to make a correction of the post that preceded this one! I was wrong when I said this: > When I load the bitcode file for this module and then dump it just before it is JITted, the “uwtable” attribute has disappeared - is this prune-eh doing its work even though it’s not listed above in the list of function pass managers? The “uwtable” attribute does not disappear! I had
2020 Nov 19
1
Problems with undef subranges in identity copies
Hi, I'm stuck trying to fix a variety of problems that occur with undef subregisters when the register coalescer eliminates identity copies. The fundamental problem is complexity from the fact that undef values are a special case since they don't have an associated VNInfo/Segment unless the value is used across blocks. For example, in this case, %0 has 2 subregisters sub0 and sub1: