shylie/llvm-project
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
llvm-project/llvm/test/Transforms/ConstraintElimination/or-implied-by-operands.ll
Florian Hahn fbcf8a8cbb
[ConstraintElim] Add (UGE, var, 0) to unsigned system for new vars. (#76262) 
The constraint system used for ConstraintElimination assumes all
varibles to be signed. This can cause missed optimization in the
unsigned system, due to missing the information that all variables are
unsigned (non-negative).

Variables can be marked as non-negative by adding Var >= 0 for all
variables. This is done for arguments on ConstraintInfo construction and
after adding new variables. This handles cases like the ones outlined in
https://discourse.llvm.org/t/why-does-llvm-not-perform-range-analysis-on-integer-values/74341

The original example shared above is now handled without this change,
but adding another variable means that instcombine won't be able to
simplify examples like https://godbolt.org/z/hTnra7zdY

Adding the extra variables comes with a slight compile-time increase
https://llvm-compile-time-tracker.com/compare.php?from=7568b36a2bc1a1e496ec29246966ffdfc3a8b87f&to=641a47f0acce7755e340447386013a2e086f03d9&stat=instructions:u

stage1-O3    stage1-ReleaseThinLTO    stage1-ReleaseLTO-g  stage1-O0-g
 +0.04%           +0.07%                   +0.05%           +0.02%
stage2-O3    stage2-O0-g    stage2-clang
  +0.05%         +0.05%        +0.05%

https://github.com/llvm/llvm-project/pull/76262
2023-12-23 15:53:48 +01:00

310 lines
8.0 KiB
LLVM
Raw Blame History

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt -passes=constraint-elimination -S %s | FileCheck %s
define i1 @test_second_or_condition_implied_by_first(i8 %x) {
; CHECK-LABEL: @test_second_or_condition_implied_by_first(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[C_1:%.*]] = icmp ule i8 [[X:%.*]], 10
; CHECK-NEXT: [[T_1:%.*]] = icmp ugt i8 [[X]], 5
; CHECK-NEXT: [[OR:%.*]] = or i1 true, [[T_1]]
; CHECK-NEXT: br i1 [[OR]], label [[THEN:%.*]], label [[ELSE:%.*]]
; CHECK: then:
; CHECK-NEXT: ret i1 false
; CHECK: else:
; CHECK-NEXT: ret i1 true
;
entry:
%c.1 = icmp ule i8 %x, 10
%t.1 = icmp ugt i8 %x, 5
%or = or i1 %c.1, %t.1
br i1 %or, label %then, label %else
then:
ret i1 0
else:
ret i1 1
}
define i1 @test_first_or_condition_implied_by_second_ops(i8 %x) {
; CHECK-LABEL: @test_first_or_condition_implied_by_second_ops(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[C_1:%.*]] = icmp ule i8 [[X:%.*]], 10
; CHECK-NEXT: [[T_1:%.*]] = icmp ugt i8 [[X]], 5
; CHECK-NEXT: [[OR:%.*]] = or i1 [[T_1]], true
; CHECK-NEXT: br i1 [[OR]], label [[THEN:%.*]], label [[ELSE:%.*]]
; CHECK: then:
; CHECK-NEXT: ret i1 false
; CHECK: else:
; CHECK-NEXT: ret i1 true
;
entry:
%c.1 = icmp ule i8 %x, 10
%t.1 = icmp ugt i8 %x, 5
%or = or i1 %t.1, %c.1
br i1 %or, label %then, label %else
then:
ret i1 0
else:
ret i1 1
}
define i1 @test_second_or_condition_implied_by_first_select_form(i8 %x) {
; CHECK-LABEL: @test_second_or_condition_implied_by_first_select_form(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[C_1:%.*]] = icmp ule i8 [[X:%.*]], 10
; CHECK-NEXT: [[T_1:%.*]] = icmp ugt i8 [[X]], 5
; CHECK-NEXT: [[OR:%.*]] = select i1 [[C_1]], i1 false, i1 [[T_1]]
; CHECK-NEXT: br i1 [[OR]], label [[THEN:%.*]], label [[ELSE:%.*]]
; CHECK: then:
; CHECK-NEXT: ret i1 false
; CHECK: else:
; CHECK-NEXT: ret i1 true
;
entry:
%c.1 = icmp ule i8 %x, 10
%t.1 = icmp ugt i8 %x, 5
%or = select i1 %c.1, i1 false, i1 %t.1
br i1 %or, label %then, label %else
then:
ret i1 0
else:
ret i1 1
}
define i1 @test_first_or_condition_implied_by_second_select_form(i8 %x) {
; CHECK-LABEL: @test_first_or_condition_implied_by_second_select_form(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[C_1:%.*]] = icmp ule i8 [[X:%.*]], 10
; CHECK-NEXT: [[T_1:%.*]] = icmp ugt i8 [[X]], 5
; CHECK-NEXT: [[OR:%.*]] = select i1 [[T_1]], i1 false, i1 [[C_1]]
; CHECK-NEXT: br i1 [[OR]], label [[THEN:%.*]], label [[ELSE:%.*]]
; CHECK: then:
; CHECK-NEXT: ret i1 false
; CHECK: else:
; CHECK-NEXT: ret i1 true
;
entry:
%c.1 = icmp ule i8 %x, 10
%t.1 = icmp ugt i8 %x, 5
%or = select i1 %t.1, i1 false, i1 %c.1
br i1 %or, label %then, label %else
then:
ret i1 0
else:
ret i1 1
}
define i1 @test_same_cond_for_or(i8 %x) {
; CHECK-LABEL: @test_same_cond_for_or(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[C_1:%.*]] = icmp ugt i8 [[X:%.*]], 10
; CHECK-NEXT: [[OR:%.*]] = or i1 false, [[C_1]]
; CHECK-NEXT: br i1 [[OR]], label [[THEN:%.*]], label [[ELSE:%.*]]
; CHECK: then:
; CHECK-NEXT: ret i1 false
; CHECK: else:
; CHECK-NEXT: ret i1 true
;
entry:
%c.1 = icmp ugt i8 %x, 10
%or = or i1 %c.1, %c.1
br i1 %or, label %then, label %else
then:
ret i1 0
else:
ret i1 1
}
define i1 @test_same_cond_for_or_select_form(i8 %x) {
; CHECK-LABEL: @test_same_cond_for_or_select_form(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[C_1:%.*]] = icmp ugt i8 [[X:%.*]], 10
; CHECK-NEXT: [[OR:%.*]] = select i1 [[C_1]], i1 false, i1 [[C_1]]
; CHECK-NEXT: br i1 [[OR]], label [[THEN:%.*]], label [[ELSE:%.*]]
; CHECK: then:
; CHECK-NEXT: ret i1 false
; CHECK: else:
; CHECK-NEXT: ret i1 true
;
entry:
%c.1 = icmp ugt i8 %x, 10
%or = select i1 %c.1, i1 false, i1 %c.1
br i1 %or, label %then, label %else
then:
ret i1 0
else:
ret i1 1
}
define i1 @test_second_or_condition_not_implied_by_first(i8 %x) {
; CHECK-LABEL: @test_second_or_condition_not_implied_by_first(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[C_1:%.*]] = icmp ugt i8 [[X:%.*]], 10
; CHECK-NEXT: [[C_2:%.*]] = icmp ugt i8 [[X]], 5
; CHECK-NEXT: [[OR:%.*]] = or i1 [[C_2]], false
; CHECK-NEXT: br i1 [[OR]], label [[THEN:%.*]], label [[ELSE:%.*]]
; CHECK: then:
; CHECK-NEXT: ret i1 false
; CHECK: else:
; CHECK-NEXT: ret i1 true
;
entry:
%c.1 = icmp ugt i8 %x, 10
%c.2 = icmp ugt i8 %x, 5
%or = or i1 %c.2, %c.1
br i1 %or, label %then, label %else
then:
ret i1 0
else:
ret i1 1
}
define i1 @test_remove_variables(i1 %c, ptr %A, i64 %B, ptr %C) {
; CHECK-LABEL: @test_remove_variables(
; CHECK-NEXT: entry:
; CHECK-NEXT: br i1 [[C:%.*]], label [[THEN_1:%.*]], label [[EXIT:%.*]]
; CHECK: then.1:
; CHECK-NEXT: [[TMP0:%.*]] = load ptr, ptr [[C:%.*]], align 8
; CHECK-NEXT: [[C_1:%.*]] = icmp ult ptr [[TMP0]], [[A:%.*]]
; CHECK-NEXT: br i1 [[C_1]], label [[THEN_2:%.*]], label [[ELSE_2:%.*]]
; CHECK: then.2:
; CHECK-NEXT: [[C_3:%.*]] = icmp sgt i64 [[B:%.*]], 0
; CHECK-NEXT: [[OR:%.*]] = or i1 true, [[C_3]]
; CHECK-NEXT: ret i1 [[OR]]
; CHECK: else.2:
; CHECK-NEXT: ret i1 false
; CHECK: exit:
; CHECK-NEXT: ret i1 true
;
entry:
br i1 %c, label %then.1, label %exit
then.1:
%0 = load ptr, ptr %C, align 8
%c.1 = icmp ult ptr %0, %A
br i1 %c.1, label %then.2, label %else.2
then.2:
%c.2 = icmp ne ptr %A, null
%c.3 = icmp sgt i64 %B, 0
%or = or i1 %c.2, %c.3
ret i1 %or
else.2:
ret i1 0
exit:
%t = icmp eq ptr null, null
ret i1 %t
}
define i1 @test_or_op_0_simplified(i32 %v) {
; CHECK-LABEL: @test_or_op_0_simplified(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[C_1:%.*]] = icmp sgt i32 [[V:%.*]], 0
; CHECK-NEXT: [[OR:%.*]] = or i1 false, [[C_1]]
; CHECK-NEXT: ret i1 [[OR]]
;
entry:
%c.1 = icmp sgt i32 %v, 0
%t.1 = icmp sgt i32 0, 0
%or = or i1 %t.1, %c.1
ret i1 %or
}
define i1 @test_or_op_1_simplified(i32 %v) {
; CHECK-LABEL: @test_or_op_1_simplified(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[C_1:%.*]] = icmp sgt i32 [[V:%.*]], 0
; CHECK-NEXT: [[OR:%.*]] = or i1 [[C_1]], false
; CHECK-NEXT: ret i1 [[OR]]
;
entry:
%c.1 = icmp sgt i32 %v, 0
%t.1 = icmp sgt i32 0, 0
%or = or i1 %c.1, %t.1
ret i1 %or
}
define i1 @test_or_used_in_false_branch(i8 %x) {
; CHECK-LABEL: @test_or_used_in_false_branch(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[C_1:%.*]] = icmp ule i8 [[X:%.*]], 10
; CHECK-NEXT: [[T_1:%.*]] = icmp ule i8 [[X]], 5
; CHECK-NEXT: [[OR:%.*]] = or i1 [[C_1]], false
; CHECK-NEXT: br i1 [[OR]], label [[THEN:%.*]], label [[ELSE:%.*]]
; CHECK: then:
; CHECK-NEXT: ret i1 [[T_1]]
; CHECK: else:
; CHECK-NEXT: ret i1 false
;
entry:
%c.1 = icmp ule i8 %x, 10
%t.1 = icmp ule i8 %x, 5
%or = or i1 %c.1, %t.1
br i1 %or, label %then, label %else
then:
ret i1 %t.1
else:
ret i1 %t.1
}
define i1 @test_or_used_in_false_branch2(i8 %x) {
; CHECK-LABEL: @test_or_used_in_false_branch2(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[C_1:%.*]] = icmp ugt i8 [[X:%.*]], 10
; CHECK-NEXT: [[T_1:%.*]] = icmp ugt i8 [[X]], 5
; CHECK-NEXT: [[OR:%.*]] = or i1 false, [[T_1]]
; CHECK-NEXT: br i1 [[OR]], label [[THEN:%.*]], label [[ELSE:%.*]]
; CHECK: then:
; CHECK-NEXT: ret i1 [[T_1]]
; CHECK: else:
; CHECK-NEXT: ret i1 false
;
entry:
%c.1 = icmp ugt i8 %x, 10
%t.1 = icmp ugt i8 %x, 5
%or = or i1 %c.1, %t.1
br i1 %or, label %then, label %else
then:
ret i1 %t.1
else:
ret i1 %t.1
}
define i1 @select_or_set_operand(ptr noundef %a, ptr noundef %b) {
; CHECK-LABEL: @select_or_set_operand(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[CMP_EQ:%.*]] = icmp eq ptr [[A:%.*]], [[B:%.*]]
; CHECK-NEXT: [[INCDEC_PTR12_I:%.*]] = getelementptr inbounds i32, ptr [[A]], i64 1
; CHECK-NEXT: [[CMP_EQ_1:%.*]] = icmp eq ptr [[INCDEC_PTR12_I]], [[B]]
; CHECK-NEXT: [[OR:%.*]] = select i1 [[CMP_EQ]], i1 true, i1 [[CMP_EQ_1]]
; CHECK-NEXT: ret i1 [[OR]]
;
entry:
%cmp.eq = icmp eq ptr %a, %b
%incdec.ptr12.i = getelementptr inbounds i32, ptr %a, i64 1
%cmp.eq.1 = icmp eq ptr %incdec.ptr12.i, %b
%or = select i1 %cmp.eq, i1 true, i1 %cmp.eq.1
ret i1 %or
}
Reference in New Issue View Git Blame Copy Permalink