| ; Test that we can evaluate the exit values of various expression types. Since |
| ; these loops all have predictable exit values we can replace the use outside |
| ; of the loop with a closed-form computation, making the loop dead. |
| ; |
| ; RUN: llvm-as < %s | opt -indvars -adce -simplifycfg | llvm-dis | not grep br |
| |
| int %polynomial_constant() { |
| br label %Loop |
| Loop: |
| %A1 = phi int [0, %0], [%A2, %Loop] |
| %B1 = phi int [0, %0], [%B2, %Loop] |
| %A2 = add int %A1, 1 |
| %B2 = add int %B1, %A1 |
| |
| %C = seteq int %A1, 1000 |
| br bool %C, label %Out, label %Loop |
| Out: |
| ret int %B2 |
| } |
| |
| int %NSquare(int %N) { |
| br label %Loop |
| Loop: |
| %X = phi int [0, %0], [%X2, %Loop] |
| %X2 = add int %X, 1 |
| %c = seteq int %X, %N |
| br bool %c, label %Out, label %Loop |
| Out: |
| %Y = mul int %X, %X |
| ret int %Y |
| } |
| |
| int %NSquareOver2(int %N) { |
| br label %Loop |
| Loop: |
| %X = phi int [0, %0], [%X2, %Loop] |
| %Y = phi int [15, %0], [%Y2, %Loop] ;; include offset of 15 for yuks |
| |
| %Y2 = add int %Y, %X |
| |
| %X2 = add int %X, 1 |
| %c = seteq int %X, %N |
| br bool %c, label %Out, label %Loop |
| Out: |
| ret int %Y2 |
| } |
| |
| int %strength_reduced() { |
| br label %Loop |
| Loop: |
| %A1 = phi int [0, %0], [%A2, %Loop] |
| %B1 = phi int [0, %0], [%B2, %Loop] |
| %A2 = add int %A1, 1 |
| %B2 = add int %B1, %A1 |
| |
| %C = seteq int %A1, 1000 |
| br bool %C, label %Out, label %Loop |
| Out: |
| ret int %B2 |
| } |
| |
| int %chrec_equals() { |
| entry: |
| br label %no_exit |
| no_exit: |
| %i0 = phi int [ 0, %entry ], [ %i1, %no_exit ] |
| %ISq = mul int %i0, %i0 |
| %i1 = add int %i0, 1 |
| %tmp.1 = setne int %ISq, 10000 ; while (I*I != 1000) |
| br bool %tmp.1, label %no_exit, label %loopexit |
| loopexit: |
| ret int %i1 |
| } |
| |
| ;; We should recognize B1 as being a recurrence, allowing us to compute the |
| ;; trip count and eliminate the loop. |
| short %cast_chrec_test() { |
| br label %Loop |
| Loop: |
| %A1 = phi int [0, %0], [%A2, %Loop] |
| %B1 = cast int %A1 to short |
| %A2 = add int %A1, 1 |
| |
| %C = seteq short %B1, 1000 |
| br bool %C, label %Out, label %Loop |
| Out: |
| ret short %B1 |
| } |
| |
| uint %linear_div_fold() { ;; for (i = 4; i != 68; i += 8) (exit with i/2) |
| entry: |
| br label %loop |
| loop: |
| %i = phi uint [ 4, %entry ], [ %i.next, %loop ] |
| %i.next = add uint %i, 8 |
| %RV = div uint %i, 2 |
| %c = setne uint %i, 68 |
| br bool %c, label %loop, label %loopexit |
| loopexit: |
| ret uint %RV |
| } |
| |