11b8699572
calculateRegisterUsage adds end points for each user of an instruction to Ends and ignores instructions not added to it, i.e. instructions with no users. This means things like stores aren't included, which in turn means values that are only used in stores are also not included for consideration. This means we underestimate the register usage in cases where the only users are things like stores. Update the code to don't skip instructions without users (i.e. not in Ends) if they have side-effects. PR: https://github.com/llvm/llvm-project/pull/126415
72 lines
2.6 KiB
LLVM
72 lines
2.6 KiB
LLVM
; REQUIRES: asserts
|
|
|
|
; RUN: opt -mtriple arm64-linux -passes=loop-vectorize -mattr=+sve -debug-only=loop-vectorize -disable-output <%s 2>&1 | FileCheck %s
|
|
|
|
; Invariant register usage calculation should take into account if the
|
|
; invariant would be used in widened instructions. Only in such cases, a vector
|
|
; register would be required for holding the invariant. For all other cases
|
|
; such as below(where usage of %0 in loop doesnt require vector register), a
|
|
; general purpose register suffices.
|
|
; Check that below test doesn't crash while calculating register usage for
|
|
; invariant %0
|
|
|
|
@string = internal unnamed_addr constant [5 x i8] c"abcd\00", align 1
|
|
|
|
define void @get_invariant_reg_usage(ptr %z) {
|
|
; CHECK-LABEL: LV: Checking a loop in 'get_invariant_reg_usage'
|
|
; CHECK: LV(REG): VF = vscale x 16
|
|
; CHECK-NEXT: LV(REG): Found max usage: 2 item
|
|
; CHECK-NEXT: LV(REG): RegisterClass: Generic::ScalarRC, 3 registers
|
|
; CHECK-NEXT: LV(REG): RegisterClass: Generic::VectorRC, 1 registers
|
|
; CHECK-NEXT: LV(REG): Found invariant usage: 2 item
|
|
; CHECK-NEXT: LV(REG): RegisterClass: Generic::ScalarRC, 2 registers
|
|
; CHECK-NEXT: LV(REG): RegisterClass: Generic::VectorRC, 8 registers
|
|
|
|
L.entry:
|
|
%0 = load i128, ptr %z, align 16
|
|
%1 = icmp slt i128 %0, 1
|
|
%a = getelementptr i8, ptr %z, i64 1
|
|
br i1 %1, label %return, label %loopbody
|
|
|
|
loopbody: ;preds = %L.entry, %loopbody
|
|
%b = phi ptr [ %2, %loopbody ], [ @string, %L.entry ]
|
|
%len_input = phi i128 [ %len, %loopbody ], [ %0, %L.entry ]
|
|
%len = add nsw i128 %len_input, -1
|
|
%2 = getelementptr i8, ptr %b, i64 1
|
|
%3 = load i8, ptr %b, align 1
|
|
store i8 %3, ptr %a, align 4
|
|
%.not = icmp eq i128 %len, 0
|
|
br i1 %.not, label %return, label %loopbody
|
|
|
|
return: ;preds = %loopexit, %L.entry
|
|
ret void
|
|
}
|
|
|
|
define void @load_and_compare_only_used_by_assume(ptr %a, ptr noalias %b) {
|
|
; CHECK-LABEL: LV: Checking a loop in 'load_and_compare_only_used_by_assume'
|
|
; CHECK: LV(REG): VF = vscale x 4
|
|
; CHECK-NEXT: LV(REG): Found max usage: 2 item
|
|
; CHECK-NEXT: LV(REG): RegisterClass: Generic::ScalarRC, 2 registers
|
|
; CHECK-NEXT: LV(REG): RegisterClass: Generic::VectorRC, 1 registers
|
|
; CHECK-NEXT: LV(REG): Found invariant usage: 0 item
|
|
|
|
entry:
|
|
br label %loop
|
|
|
|
loop:
|
|
%iv = phi i64 [ 0, %entry ], [ %iv.next, %loop ]
|
|
%gep.a = getelementptr inbounds i32, ptr %a, i64 %iv
|
|
%l.a = load i32, ptr %gep.a
|
|
%gep.b = getelementptr inbounds i32, ptr %b, i64 %iv
|
|
%l.b = load i32, ptr %gep.b
|
|
%c = icmp ugt i32 %l.b, 10
|
|
call void @llvm.assume(i1 %c)
|
|
store i32 %l.a, ptr %gep.b
|
|
%iv.next = add i64 %iv, 1
|
|
%ec = icmp eq i64 %iv.next, 1000
|
|
br i1 %ec, label %exit, label %loop
|
|
|
|
exit:
|
|
ret void
|
|
}
|