known-non-zero.ll
4.42 KB
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; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -instcombine -S | FileCheck %s
declare i64 @llvm.cttz.i64(i64, i1)
declare i64 @llvm.ctlz.i64(i64, i1)
declare <8 x i64> @llvm.cttz.v8i64(<8 x i64>, i1)
define i32 @test0(i64 %x) {
; CHECK-LABEL: @test0(
; CHECK-NEXT: start:
; CHECK-NEXT: [[C:%.*]] = icmp eq i64 [[X:%.*]], 0
; CHECK-NEXT: br i1 [[C]], label [[EXIT:%.*]], label [[NON_ZERO:%.*]]
; CHECK: non_zero:
; CHECK-NEXT: [[CTZ:%.*]] = call i64 @llvm.cttz.i64(i64 [[X]], i1 true), !range !0
; CHECK-NEXT: [[CTZ32:%.*]] = trunc i64 [[CTZ]] to i32
; CHECK-NEXT: br label [[EXIT]]
; CHECK: exit:
; CHECK-NEXT: [[RES:%.*]] = phi i32 [ [[CTZ32]], [[NON_ZERO]] ], [ 0, [[START:%.*]] ]
; CHECK-NEXT: ret i32 [[RES]]
;
start:
%c = icmp eq i64 %x, 0
br i1 %c, label %exit, label %non_zero
non_zero:
%ctz = call i64 @llvm.cttz.i64(i64 %x, i1 false)
%ctz32 = trunc i64 %ctz to i32
br label %exit
exit:
%res = phi i32 [ %ctz32, %non_zero ], [ 0, %start ]
ret i32 %res
}
define i32 @test1(i64 %x) {
; CHECK-LABEL: @test1(
; CHECK-NEXT: start:
; CHECK-NEXT: [[C:%.*]] = icmp eq i64 [[X:%.*]], 0
; CHECK-NEXT: br i1 [[C]], label [[EXIT:%.*]], label [[NON_ZERO:%.*]]
; CHECK: non_zero:
; CHECK-NEXT: [[CTZ:%.*]] = call i64 @llvm.ctlz.i64(i64 [[X]], i1 true), !range !0
; CHECK-NEXT: [[CTZ32:%.*]] = trunc i64 [[CTZ]] to i32
; CHECK-NEXT: br label [[EXIT]]
; CHECK: exit:
; CHECK-NEXT: [[RES:%.*]] = phi i32 [ [[CTZ32]], [[NON_ZERO]] ], [ 0, [[START:%.*]] ]
; CHECK-NEXT: ret i32 [[RES]]
;
start:
%c = icmp eq i64 %x, 0
br i1 %c, label %exit, label %non_zero
non_zero:
%ctz = call i64 @llvm.ctlz.i64(i64 %x, i1 false)
%ctz32 = trunc i64 %ctz to i32
br label %exit
exit:
%res = phi i32 [ %ctz32, %non_zero ], [ 0, %start ]
ret i32 %res
}
define <8 x i64> @test2(<8 x i64> %x) {
; CHECK-LABEL: @test2(
; CHECK-NEXT: start:
; CHECK-NEXT: [[A:%.*]] = icmp eq <8 x i64> [[X:%.*]], zeroinitializer
; CHECK-NEXT: [[B:%.*]] = bitcast <8 x i1> [[A]] to i8
; CHECK-NEXT: [[C:%.*]] = icmp eq i8 [[B]], 0
; CHECK-NEXT: br i1 [[C]], label [[EXIT:%.*]], label [[NON_ZERO:%.*]]
; CHECK: non_zero:
; CHECK-NEXT: [[CTZ:%.*]] = call <8 x i64> @llvm.cttz.v8i64(<8 x i64> [[X]], i1 false)
; CHECK-NEXT: br label [[EXIT]]
; CHECK: exit:
; CHECK-NEXT: [[RES:%.*]] = phi <8 x i64> [ [[CTZ]], [[NON_ZERO]] ], [ zeroinitializer, [[START:%.*]] ]
; CHECK-NEXT: ret <8 x i64> [[RES]]
;
start:
%a = icmp eq <8 x i64> %x, zeroinitializer
%b = bitcast <8 x i1> %a to i8
%c = icmp eq i8 %b, 0
br i1 %c, label %exit, label %non_zero
non_zero:
; NB: We cannot determine that vectors are known to be zero based
; on the dominating condition
%ctz = call <8 x i64> @llvm.cttz.v8i64(<8 x i64> %x, i1 false)
br label %exit
exit:
%res = phi <8 x i64> [ %ctz, %non_zero ], [ zeroinitializer, %start ]
ret <8 x i64> %res
}
; Test that exposed a bug in the PHI handling after D60846. No folding should happen here!
define void @D60846_misompile(i1* %p) {
; CHECK-LABEL: @D60846_misompile(
; CHECK-NEXT: entry:
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[I:%.*]] = phi i16 [ 0, [[ENTRY:%.*]] ], [ [[I_INC:%.*]], [[COMMON:%.*]] ]
; CHECK-NEXT: [[IS_ZERO:%.*]] = icmp eq i16 [[I]], 0
; CHECK-NEXT: br i1 [[IS_ZERO]], label [[COMMON]], label [[NON_ZERO:%.*]]
; CHECK: non_zero:
; CHECK-NEXT: [[IS_ONE:%.*]] = icmp eq i16 [[I]], 1
; CHECK-NEXT: store i1 [[IS_ONE]], i1* [[P:%.*]], align 1
; CHECK-NEXT: br label [[COMMON]]
; CHECK: common:
; CHECK-NEXT: [[I_INC]] = add i16 [[I]], 1
; CHECK-NEXT: [[LOOP_COND:%.*]] = icmp ult i16 [[I_INC]], 2
; CHECK-NEXT: br i1 [[LOOP_COND]], label [[LOOP]], label [[EXIT:%.*]]
; CHECK: exit:
; CHECK-NEXT: ret void
;
entry:
br label %loop
loop: ; preds = %common, %entry
%i = phi i16 [ 0, %entry ], [ %i.inc, %common ]
%is_zero = icmp eq i16 %i, 0
br i1 %is_zero, label %common, label %non_zero
non_zero: ; preds = %loop
%is_one = icmp eq i16 %i, 1
store i1 %is_one, i1* %p
br label %common
common: ; preds = %non_zero, %loop
%i.inc = add i16 %i, 1
%loop_cond = icmp ult i16 %i.inc, 2
br i1 %loop_cond, label %loop, label %exit
exit: ; preds = %common
ret void
}