clamp.ll
3.93 KB
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; RUN: opt -verify-loop-info -irce-print-changed-loops -irce -S < %s 2>&1 | FileCheck %s
; RUN: opt -verify-loop-info -irce-print-changed-loops -passes='require<branch-prob>,loop(irce)' -S < %s 2>&1 | FileCheck %s
; The test demonstrates that incorrect behavior of Clamp may lead to incorrect
; calculation of post-loop exit condition.
; CHECK-LABEL: irce: in function test_01: constrained Loop at depth 1 containing: %loop<header><exiting>,%in_bounds<exiting>,%not_zero<latch><exiting>
; CHECK-NOT: irce: in function test_02: constrained Loop
define void @test_01() {
; CHECK-LABEL: test_01
entry:
%indvars.iv.next467 = add nuw nsw i64 2, 1
%length.i167 = load i32, i32 addrspace(1)* undef, align 8
%tmp21 = zext i32 %length.i167 to i64
%tmp34 = load atomic i32, i32 addrspace(1)* undef unordered, align 4
%tmp35 = add i32 %tmp34, -9581
%tmp36 = icmp ugt i32 %length.i167, 1
br i1 %tmp36, label %preheader, label %exit
exit: ; preds = %in_bounds, %loop, %not_zero, %entry
ret void
preheader: ; preds = %entry
; CHECK: preheader:
; CHECK-NEXT: %length_gep.i146 = getelementptr inbounds i8, i8 addrspace(1)* undef, i64 8
; CHECK-NEXT: %length_gep_typed.i147 = bitcast i8 addrspace(1)* undef to i32 addrspace(1)*
; CHECK-NEXT: %tmp43 = icmp ult i64 %indvars.iv.next467, %tmp21
; CHECK-NEXT: [[C0:%[^ ]+]] = icmp ugt i64 %tmp21, 1
; CHECK-NEXT: %exit.mainloop.at = select i1 [[C0]], i64 %tmp21, i64 1
; CHECK-NEXT: [[C1:%[^ ]+]] = icmp ult i64 1, %exit.mainloop.at
; CHECK-NEXT: br i1 [[C1]], label %loop.preheader, label %main.pseudo.exit
%length_gep.i146 = getelementptr inbounds i8, i8 addrspace(1)* undef, i64 8
%length_gep_typed.i147 = bitcast i8 addrspace(1)* undef to i32 addrspace(1)*
%tmp43 = icmp ult i64 %indvars.iv.next467, %tmp21
br label %loop
not_zero: ; preds = %in_bounds
; CHECK: not_zero:
; CHECK: %tmp56 = icmp ult i64 %indvars.iv.next, %tmp21
; CHECK-NEXT: [[COND:%[^ ]+]] = icmp ult i64 %indvars.iv.next, %exit.mainloop.at
; CHECK-NEXT: br i1 [[COND]], label %loop, label %main.exit.selector
%tmp51 = trunc i64 %indvars.iv.next to i32
%tmp53 = mul i32 %tmp51, %tmp51
%tmp54 = add i32 %tmp53, -9582
%tmp55 = add i32 %tmp54, %tmp62
%tmp56 = icmp ult i64 %indvars.iv.next, %tmp21
br i1 %tmp56, label %loop, label %exit
loop: ; preds = %not_zero, %preheader
%tmp62 = phi i32 [ 1, %preheader ], [ %tmp55, %not_zero ]
%indvars.iv750 = phi i64 [ 1, %preheader ], [ %indvars.iv.next, %not_zero ]
%length.i148 = load i32, i32 addrspace(1)* %length_gep_typed.i147, align 8
%tmp68 = zext i32 %length.i148 to i64
%tmp97 = icmp ult i64 2, %tmp68
%or.cond = and i1 %tmp43, %tmp97
%tmp99 = icmp ult i64 %indvars.iv750, %tmp21
%or.cond1 = and i1 %or.cond, %tmp99
br i1 %or.cond1, label %in_bounds, label %exit
in_bounds: ; preds = %loop
%indvars.iv.next = add nuw nsw i64 %indvars.iv750, 3
%tmp107 = icmp ult i64 %indvars.iv.next, 2
br i1 %tmp107, label %not_zero, label %exit
}
define void @test_02() {
; Now IRCE is smart enough to understand that the safe range here is empty.
; Previously it executed the entire loop in safe preloop and never actually
; entered the main loop.
entry:
br label %loop
loop: ; preds = %in_bounds, %entry
%iv1 = phi i64 [ 3, %entry ], [ %iv1.next, %in_bounds ]
%iv2 = phi i64 [ 4294967295, %entry ], [ %iv2.next, %in_bounds ]
%iv2.offset = add i64 %iv2, 1
%rc = icmp ult i64 %iv2.offset, 400
br i1 %rc, label %in_bounds, label %bci_321
bci_321: ; preds = %in_bounds, %loop
ret void
in_bounds: ; preds = %loop
%iv1.next = add nuw nsw i64 %iv1, 2
%iv2.next = add nuw nsw i64 %iv2, 2
%cond = icmp ugt i64 %iv1, 204
br i1 %cond, label %bci_321, label %loop
}