/
bad_expander.ll
135 lines (107 loc) · 4.54 KB
/
bad_expander.ll
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; RUN: opt -verify-loop-info -irce-print-changed-loops -passes=irce -S < %s 2>&1 | FileCheck %s
; RUN: opt -verify-loop-info -irce-print-changed-loops -passes='require<branch-prob>,irce' -S < %s 2>&1 | FileCheck %s
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128-ni:1"
target triple = "x86_64-unknown-linux-gnu"
; IRCE should fail here because the preheader's exiting value is a phi from the
; loop, and this value cannot be expanded at loop's preheader.
; CHECK-NOT: irce: in function test_01: constrained Loop
; CHECK-NOT: irce: in function test_02: constrained Loop
; CHECK-LABEL: irce: in function test_03: constrained Loop
define void @test_01() {
; CHECK-NOT: irce: in function test_01: constrained Loop
; CHECK-LABEL: test_01
; CHECK-NOT: preloop
; CHECK-NOT: postloop
; CHECK-NOT: br i1 false
; CHECK-NOT: br i1 true
entry:
br label %loop
exit: ; preds = %guarded, %loop
ret void
loop: ; preds = %guarded, %entry
%iv = phi i64 [ 380, %entry ], [ %limit, %guarded ]
%bad_phi = phi i32 [ 3, %entry ], [ %bad_phi.next, %guarded ]
%bad_phi.next = add nuw nsw i32 %bad_phi, 1
%iv.next = add nuw nsw i64 %iv, 1
%rc = icmp slt i64 %iv.next, 5
br i1 %rc, label %guarded, label %exit
guarded:
%limit = add nsw i64 %iv, -1
%tmp5 = add nuw nsw i32 %bad_phi, 8
%tmp6 = zext i32 %tmp5 to i64
%tmp7 = icmp eq i64 %limit, %tmp6
br i1 %tmp7, label %exit, label %loop
}
; This test should fail because we are unable to prove that the division is
; safe to expand it to preheader: if we exit by maybe_exit condition, it is
; unsafe to execute it there.
define void @test_02(ptr %p1, ptr %p2, i1 %maybe_exit) {
; CHECK-LABEL: test_02
; CHECK-NOT: preloop
; CHECK-NOT: postloop
; CHECK-NOT: br i1 false
; CHECK-NOT: br i1 true
entry:
%num = load i64, ptr %p1, align 4, !range !0
%denom = load i64, ptr %p2, align 4, !range !0
br label %loop
exit: ; preds = %guarded, %loop
ret void
loop: ; preds = %guarded, %entry
%iv = phi i64 [ 0, %entry ], [ %iv.next, %guarded ]
%iv.next = add nuw nsw i64 %iv, 1
br i1 %maybe_exit, label %range_check, label %exit
range_check:
%div_result = udiv i64 %num, %denom
%rc = icmp slt i64 %iv.next, %div_result
br i1 %rc, label %guarded, label %exit
guarded:
%gep = getelementptr i64, ptr %p1, i64 %iv.next
%loaded = load i64, ptr %gep, align 4
%tmp7 = icmp slt i64 %iv.next, 1000
br i1 %tmp7, label %loop, label %exit
}
define void @test_03(ptr %p1, ptr %p2, i1 %maybe_exit) {
; Show that IRCE would hit test_02 if the division was safe (denom not zero).
; CHECK-LABEL: test_03
; CHECK: entry:
; CHECK-NEXT: %num = load i64, ptr %p1, align 4
; CHECK-NEXT: [[DIV:%[^ ]+]] = udiv i64 %num, 13
; CHECK-NEXT: [[DIV_MINUS_1:%[^ ]+]] = add nsw i64 [[DIV]], -1
; CHECK-NEXT: %exit.mainloop.at = call i64 @llvm.smax.i64(i64 [[DIV_MINUS_1]], i64 0)
; CHECK-NEXT: [[COMP2:%[^ ]+]] = icmp slt i64 0, %exit.mainloop.at
; CHECK-NEXT: br i1 [[COMP2]], label %loop.preheader, label %main.pseudo.exit
; CHECK-NOT: preloop
; CHECK: loop:
; CHECK-NEXT: %iv = phi i64 [ %iv.next, %guarded ], [ 0, %loop.preheader ]
; CHECK-NEXT: %iv.next = add nuw nsw i64 %iv, 1
; CHECK-NEXT: %rc = icmp slt i64 %iv.next, %div_result
; CHECK-NEXT: %or.cond = select i1 %maybe_exit, i1 true, i1 false
; CHECK-NEXT: br i1 %or.cond, label %guarded, label %exit.loopexit1
; CHECK: guarded:
; CHECK-NEXT: %gep = getelementptr i64, ptr %p1, i64 %iv.next
; CHECK-NEXT: %loaded = load i64, ptr %gep, align 4
; CHECK-NEXT: %tmp7 = icmp slt i64 %iv.next, 1000
; CHECK-NEXT: [[EXIT_MAIN_LOOP:%[^ ]+]] = icmp slt i64 %iv.next, %exit.mainloop.at
; CHECK-NEXT: br i1 [[EXIT_MAIN_LOOP]], label %loop, label %main.exit.selector
; CHECK: postloop
entry:
%num = load i64, ptr %p1, align 4, !range !0
br label %loop
exit: ; preds = %guarded, %loop
ret void
loop: ; preds = %guarded, %entry
%iv = phi i64 [ 0, %entry ], [ %iv.next, %guarded ]
%iv.next = add nuw nsw i64 %iv, 1
br i1 %maybe_exit, label %range_check, label %exit
range_check:
%div_result = udiv i64 %num, 13
%rc = icmp slt i64 %iv.next, %div_result
br i1 %rc, label %guarded, label %exit
guarded:
%gep = getelementptr i64, ptr %p1, i64 %iv.next
%loaded = load i64, ptr %gep, align 4
%tmp7 = icmp slt i64 %iv.next, 1000
br i1 %tmp7, label %loop, label %exit
}
!0 = !{i64 0, i64 100}