| ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py |
| ; RUN: opt -S -passes=jump-threading < %s | FileCheck %s |
| |
| ; Check that the heuristic for avoiding accidental introduction of irreducible |
| ; loops doesn't also prevent us from threading simple constructs where this |
| ; isn't a problem. |
| |
| declare void @opaque_body() |
| |
| define void @jump_threading_loopheader() { |
| ; CHECK-LABEL: @jump_threading_loopheader( |
| ; CHECK-NEXT: top: |
| ; CHECK-NEXT: br label [[ENTRY:%.*]] |
| ; CHECK: entry: |
| ; CHECK-NEXT: [[IND:%.*]] = phi i32 [ 0, [[TOP:%.*]] ], [ [[NEXTIND:%.*]], [[LATCH:%.*]] ] |
| ; CHECK-NEXT: [[NEXTIND]] = add i32 [[IND]], 1 |
| ; CHECK-NEXT: [[CMP:%.*]] = icmp ule i32 [[IND]], 10 |
| ; CHECK-NEXT: br i1 [[CMP]], label [[LATCH]], label [[EXIT:%.*]] |
| ; CHECK: latch: |
| ; CHECK-NEXT: call void @opaque_body() |
| ; CHECK-NEXT: br label [[ENTRY]] |
| ; CHECK: exit: |
| ; CHECK-NEXT: ret void |
| ; |
| top: |
| br label %entry |
| |
| entry: |
| %ind = phi i32 [0, %top], [%nextind, %latch] |
| %nextind = add i32 %ind, 1 |
| %cmp = icmp ule i32 %ind, 10 |
| br i1 %cmp, label %body, label %latch |
| |
| body: |
| call void @opaque_body() |
| br label %latch |
| |
| latch: |
| %cond = phi i2 [1, %entry], [2, %body] |
| switch i2 %cond, label %unreach [ |
| i2 2, label %entry |
| i2 1, label %exit |
| ] |
| |
| unreach: |
| unreachable |
| |
| exit: |
| ret void |
| } |
| |
| ; We also need to check the opposite order of the branches, in the switch |
| ; instruction because jump-threading relies on that to decide which edge to |
| ; try to thread first. |
| define void @jump_threading_loopheader2() { |
| ; CHECK-LABEL: @jump_threading_loopheader2( |
| ; CHECK-NEXT: top: |
| ; CHECK-NEXT: br label [[ENTRY:%.*]] |
| ; CHECK: entry: |
| ; CHECK-NEXT: [[IND:%.*]] = phi i32 [ 0, [[TOP:%.*]] ], [ [[NEXTIND:%.*]], [[LATCH:%.*]] ] |
| ; CHECK-NEXT: [[NEXTIND]] = add i32 [[IND]], 1 |
| ; CHECK-NEXT: [[CMP:%.*]] = icmp ule i32 [[IND]], 10 |
| ; CHECK-NEXT: br i1 [[CMP]], label [[EXIT:%.*]], label [[LATCH]] |
| ; CHECK: latch: |
| ; CHECK-NEXT: br label [[ENTRY]] |
| ; CHECK: exit: |
| ; CHECK-NEXT: call void @opaque_body() |
| ; CHECK-NEXT: ret void |
| ; |
| top: |
| br label %entry |
| |
| entry: |
| %ind = phi i32 [0, %top], [%nextind, %latch] |
| %nextind = add i32 %ind, 1 |
| %cmp = icmp ule i32 %ind, 10 |
| br i1 %cmp, label %body, label %latch |
| |
| body: |
| call void @opaque_body() |
| br label %latch |
| |
| latch: |
| %cond = phi i2 [1, %entry], [2, %body] |
| switch i2 %cond, label %unreach [ |
| i2 1, label %entry |
| i2 2, label %exit |
| ] |
| |
| unreach: |
| unreachable |
| |
| exit: |
| ret void |
| } |
| |
| ; Check if we can handle undef branch condition. |
| define void @jump_threading_loopheader3() { |
| ; CHECK-LABEL: @jump_threading_loopheader3( |
| ; CHECK-NEXT: top: |
| ; CHECK-NEXT: br label [[ENTRY:%.*]] |
| ; CHECK: entry: |
| ; CHECK-NEXT: [[IND:%.*]] = phi i32 [ 0, [[TOP:%.*]] ], [ [[NEXTIND:%.*]], [[LATCH:%.*]] ] |
| ; CHECK-NEXT: [[NEXTIND]] = add i32 [[IND]], 1 |
| ; CHECK-NEXT: [[CMP:%.*]] = icmp ule i32 [[IND]], 10 |
| ; CHECK-NEXT: br i1 [[CMP]], label [[LATCH]], label [[EXIT:%.*]] |
| ; CHECK: latch: |
| ; CHECK-NEXT: call void @opaque_body() |
| ; CHECK-NEXT: br label [[ENTRY]] |
| ; CHECK: exit: |
| ; CHECK-NEXT: ret void |
| ; |
| top: |
| br label %entry |
| |
| entry: |
| %ind = phi i32 [0, %top], [%nextind, %latch] |
| %nextind = add i32 %ind, 1 |
| %cmp = icmp ule i32 %ind, 10 |
| br i1 %cmp, label %body, label %latch |
| |
| body: |
| call void @opaque_body() |
| br label %latch |
| |
| latch: |
| %phi = phi i32 [undef, %entry], [0, %body] |
| %cmp1 = icmp eq i32 %phi, 0 |
| br i1 %cmp1, label %entry, label %exit |
| |
| exit: |
| ret void |
| } |