[LLVMdev] LLVM 2.6 -> SVN breaks this

[Jon Harrop]

The LLVM 2.6-compatible IR below is derived from the HLVM test suite and is 
one of the things I've noticed going wrong. However, I just discovered that 
it works with LLVM 2.6 and with LLVM SVN when run through lli or llc 
without -tailcallopt but when I use:

$ llvm-as -f aout.ll
$ llc -tailcallopt -f aout.bc -o aout.s
$ gcc -lm aout.s -o aout

and the latest LLVM SVN it starts to print incorrect output (it is supposed to 
print the Mandelbrot set in ASCII). Perhaps this is a repro for the new 
TCO-related bug?

  ; ModuleID = 'aout.bc'
  
  %0 = type { i32, %1 }
  %1 = type { i8*, i32, i8*, i8* }
  %2 = type { i32 (%1)*, i32 (%1)* }
  %3 = type { i32, %1, %0, %1 }
  %4 = type { i32, double, double, double, double }
  %5 = type { i32, i32, i32 }
  %6 = type { i32, i32 }
  
  @buf25 = global [2 x i8] c" \00"                  ; <[2 x i8]*> [#uses=1]
  @buf26 = global [2 x i8] c".\00"                  ; <[2 x i8]*> [#uses=1]
  @buf27 = global [2 x i8] c"\0A\00"                ; <[2 x i8]*> [#uses=1]
  
  declare i32 @putchar(i32)
  
  declare void @exit(i32)
  
  declare i32 @printf(i8*, ...)
  
  define fastcc i32 @gc_check() {
    ret i32 0
  }
  
  define fastcc i32 @pixel(i32, double, double, double, double) {
  entry:
    br label %start
  
  start:                                            ; preds = %entry
    %5 = insertvalue %4 undef, i32 %0, 0            ; <%4> [#uses=1]
    %6 = insertvalue %4 %5, double %1, 1            ; <%4> [#uses=1]
    %7 = insertvalue %4 %6, double %2, 2            ; <%4> [#uses=1]
    %8 = insertvalue %4 %7, double %3, 3            ; <%4> [#uses=1]
    %9 = insertvalue %4 %8, double %4, 4            ; <%4> [#uses=0]
    %10 = call fastcc i32 @gc_check()               ; <i32> [#uses=0]
    %11 = icmp eq i32 %0, 65536                     ; <i1> [#uses=1]
    br i1 %11, label %pass, label %fail
  
  fail:                                             ; preds = %start
    %12 = fmul double %1, %1                        ; <double> [#uses=1]
    %13 = fmul double %2, %2                        ; <double> [#uses=1]
    %14 = fadd double %12, %13                      ; <double> [#uses=1]
    %15 = fcmp oge double %14, 4.000000e+00         ; <i1> [#uses=1]
    br i1 %15, label %pass2, label %fail1
  
  pass:                                             ; preds = %start
    %16 = call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([2 x i8]* 
@buf25, i32 0, i32 0)) ; <i32> [#uses=0]
    ret i32 0
  
  fail1:                                            ; preds = %fail
    %17 = add i32 %0, 1                             ; <i32> [#uses=1]
    %18 = fmul double %1, %1                        ; <double> [#uses=1]
    %19 = fmul double %2, %2                        ; <double> [#uses=1]
    %20 = fsub double %18, %19                      ; <double> [#uses=1]
    %21 = fadd double %20, %3                       ; <double> [#uses=1]
    %22 = fmul double 2.000000e+00, %1              ; <double> [#uses=1]
    %23 = fmul double %22, %2                       ; <double> [#uses=1]
    %24 = fadd double %23, %4                       ; <double> [#uses=1]
    %25 = tail call fastcc i32 @pixel(i32 %17, double %21, double %24, 
double %3, double %4) ; <i32> [#uses=1]
    ret i32 %25
  
  pass2:                                            ; preds = %fail
    %26 = call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([2 x i8]* 
@buf26, i32 0, i32 0)) ; <i32> [#uses=0]
    ret i32 0
  }
  
  define fastcc i32 @row(i32, i32, i32) {
  entry:
    br label %start
  
  start:                                            ; preds = %entry
    %3 = insertvalue %5 undef, i32 %0, 0            ; <%5> [#uses=1]
    %4 = insertvalue %5 %3, i32 %1, 1               ; <%5> [#uses=1]
    %5 = insertvalue %5 %4, i32 %2, 2               ; <%5> [#uses=0]
    %6 = call fastcc i32 @gc_check()                ; <i32> [#uses=0]
    %7 = icmp sgt i32 %0, %2                        ; <i1> [#uses=1]
    br i1 %7, label %pass, label %fail
  
  fail:                                             ; preds = %start
    %8 = sitofp i32 %0 to double                    ; <double> [#uses=1]
    %9 = fmul double 2.000000e+00, %8               ; <double> [#uses=1]
    %10 = sitofp i32 %2 to double                   ; <double> [#uses=1]
    %11 = fdiv double %9, %10                       ; <double> [#uses=1]
    %12 = fsub double %11, 1.500000e+00             ; <double> [#uses=1]
    %13 = sitofp i32 %1 to double                   ; <double> [#uses=1]
    %14 = fmul double 2.000000e+00, %13             ; <double> [#uses=1]
    %15 = sitofp i32 %2 to double                   ; <double> [#uses=1]
    %16 = fdiv double %14, %15                      ; <double> [#uses=1]
    %17 = fsub double %16, 1.000000e+00             ; <double> [#uses=1]
    %18 = call fastcc i32 @pixel(i32 0, double 0.000000e+00, double 
0.000000e+00, double %12, double %17) ; <i32> [#uses=0]
    %19 = add i32 %0, 1                             ; <i32> [#uses=1]
    %20 = tail call fastcc i32 @row(i32 %19, i32 %1, i32 %2) ; <i32> [#uses=1]
    ret i32 %20
  
  pass:                                             ; preds = %start
    ret i32 0
  }
  
  define fastcc i32 @col(i32, i32) {
  entry:
    br label %start
  
  start:                                            ; preds = %entry
    %2 = insertvalue %6 undef, i32 %0, 0            ; <%6> [#uses=1]
    %3 = insertvalue %6 %2, i32 %1, 1               ; <%6> [#uses=0]
    %4 = call fastcc i32 @gc_check()                ; <i32> [#uses=0]
    %5 = icmp sgt i32 %0, %1                        ; <i1> [#uses=1]
    br i1 %5, label %pass, label %fail
  
  fail:                                             ; preds = %start
    %6 = call fastcc i32 @row(i32 0, i32 %0, i32 %1) ; <i32> [#uses=0]
    %7 = call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([2 x i8]* 
@buf27, i32 0, i32 0)) ; <i32> [#uses=0]
    %8 = add i32 %0, 1                              ; <i32> [#uses=1]
    %9 = tail call fastcc i32 @col(i32 %8, i32 %1)  ; <i32> [#uses=1]
    ret i32 %9
  
  pass:                                             ; preds = %start
    ret i32 0
  }
  
  define i32 @main() {
    %1 = call fastcc i32 @col(i32 0, i32 77)
    ret i32 0
  }

-- 
Dr Jon Harrop, Flying Frog Consultancy Ltd.
http://www.ffconsultancy.com/?e