051ec9f5f4
Split impliesPoison into two recursive walks, one over V, the other over ValAssumedPoison. This allows us to reason about poison implications in a number of additional cases that are important in practice. This is a generalized form of D94859, which handles the cmp to cmp implication in particular. Differential Revision: https://reviews.llvm.org/D94866
179 lines
5.4 KiB
LLVM
179 lines
5.4 KiB
LLVM
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
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; RUN: opt -S -instcombine -instcombine-unsafe-select-transform=0 < %s | FileCheck %s
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; Should not be converted to "and", which has different poison semantics.
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define i1 @logical_and(i1 %a, i1 %b) {
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; CHECK-LABEL: @logical_and(
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; CHECK-NEXT: [[RES:%.*]] = select i1 [[A:%.*]], i1 [[B:%.*]], i1 false
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; CHECK-NEXT: ret i1 [[RES]]
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;
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%res = select i1 %a, i1 %b, i1 false
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ret i1 %res
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}
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; Should not be converted to "or", which has different poison semantics.
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define i1 @logical_or(i1 %a, i1 %b) {
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; CHECK-LABEL: @logical_or(
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; CHECK-NEXT: [[RES:%.*]] = select i1 [[A:%.*]], i1 true, i1 [[B:%.*]]
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; CHECK-NEXT: ret i1 [[RES]]
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;
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%res = select i1 %a, i1 true, i1 %b
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ret i1 %res
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}
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; Canonicalize to logical and form, even if that requires adding a "not".
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define i1 @logical_and_not(i1 %a, i1 %b) {
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; CHECK-LABEL: @logical_and_not(
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; CHECK-NEXT: [[NOT_A:%.*]] = xor i1 [[A:%.*]], true
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; CHECK-NEXT: [[RES:%.*]] = select i1 [[NOT_A]], i1 [[B:%.*]], i1 false
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; CHECK-NEXT: ret i1 [[RES]]
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;
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%res = select i1 %a, i1 false, i1 %b
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ret i1 %res
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}
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; Canonicalize to logical or form, even if that requires adding a "not".
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define i1 @logical_or_not(i1 %a, i1 %b) {
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; CHECK-LABEL: @logical_or_not(
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; CHECK-NEXT: [[NOT_A:%.*]] = xor i1 [[A:%.*]], true
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; CHECK-NEXT: [[RES:%.*]] = select i1 [[NOT_A]], i1 true, i1 [[B:%.*]]
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; CHECK-NEXT: ret i1 [[RES]]
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;
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%res = select i1 %a, i1 %b, i1 true
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ret i1 %res
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}
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; These are variants where condition or !condition is used to represent true
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; or false in one of the select arms. It should be canonicalized to the
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; constants.
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define i1 @logical_and_cond_reuse(i1 %a, i1 %b) {
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; CHECK-LABEL: @logical_and_cond_reuse(
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; CHECK-NEXT: [[RES:%.*]] = select i1 [[A:%.*]], i1 [[B:%.*]], i1 false
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; CHECK-NEXT: ret i1 [[RES]]
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;
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%res = select i1 %a, i1 %b, i1 %a
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ret i1 %res
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}
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define i1 @logical_or_cond_reuse(i1 %a, i1 %b) {
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; CHECK-LABEL: @logical_or_cond_reuse(
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; CHECK-NEXT: [[RES:%.*]] = select i1 [[A:%.*]], i1 true, i1 [[B:%.*]]
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; CHECK-NEXT: ret i1 [[RES]]
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;
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%res = select i1 %a, i1 %a, i1 %b
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ret i1 %res
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}
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define i1 @logical_and_not_cond_reuse(i1 %a, i1 %b) {
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; CHECK-LABEL: @logical_and_not_cond_reuse(
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; CHECK-NEXT: [[A_NOT:%.*]] = xor i1 [[A:%.*]], true
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; CHECK-NEXT: [[RES:%.*]] = select i1 [[A_NOT]], i1 true, i1 [[B:%.*]]
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; CHECK-NEXT: ret i1 [[RES]]
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;
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%a.not = xor i1 %a, true
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%res = select i1 %a, i1 %b, i1 %a.not
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ret i1 %res
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}
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define i1 @logical_or_not_cond_reuse(i1 %a, i1 %b) {
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; CHECK-LABEL: @logical_or_not_cond_reuse(
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; CHECK-NEXT: [[A_NOT:%.*]] = xor i1 [[A:%.*]], true
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; CHECK-NEXT: [[RES:%.*]] = select i1 [[A_NOT]], i1 [[B:%.*]], i1 false
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; CHECK-NEXT: ret i1 [[RES]]
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;
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%a.not = xor i1 %a, true
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%res = select i1 %a, i1 %a.not, i1 %b
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ret i1 %res
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}
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; Safe to convert to or due to poison implication.
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define i1 @logical_or_implies(i32 %x) {
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; CHECK-LABEL: @logical_or_implies(
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; CHECK-NEXT: [[C1:%.*]] = icmp eq i32 [[X:%.*]], 0
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; CHECK-NEXT: [[C2:%.*]] = icmp eq i32 [[X]], 42
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; CHECK-NEXT: [[RES:%.*]] = or i1 [[C1]], [[C2]]
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; CHECK-NEXT: ret i1 [[RES]]
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;
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%c1 = icmp eq i32 %x, 0
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%c2 = icmp eq i32 %x, 42
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%res = select i1 %c1, i1 true, i1 %c2
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ret i1 %res
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}
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; Will fold after conversion to or.
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define i1 @logical_or_implies_folds(i32 %x) {
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; CHECK-LABEL: @logical_or_implies_folds(
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; CHECK-NEXT: ret i1 true
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;
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%c1 = icmp slt i32 %x, 0
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%c2 = icmp sge i32 %x, 0
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%res = select i1 %c1, i1 true, i1 %c2
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ret i1 %res
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}
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; Safe to convert to and due to poison implication.
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define i1 @logical_and_implies(i32 %x) {
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; CHECK-LABEL: @logical_and_implies(
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; CHECK-NEXT: [[C1:%.*]] = icmp ne i32 [[X:%.*]], 0
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; CHECK-NEXT: [[C2:%.*]] = icmp ne i32 [[X]], 42
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; CHECK-NEXT: [[RES:%.*]] = and i1 [[C1]], [[C2]]
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; CHECK-NEXT: ret i1 [[RES]]
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;
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%c1 = icmp ne i32 %x, 0
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%c2 = icmp ne i32 %x, 42
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%res = select i1 %c1, i1 %c2, i1 false
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ret i1 %res
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}
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; Will fold after conversion to and.
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define i1 @logical_and_implies_folds(i32 %x) {
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; CHECK-LABEL: @logical_and_implies_folds(
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; CHECK-NEXT: [[C1:%.*]] = icmp ugt i32 [[X:%.*]], 42
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; CHECK-NEXT: ret i1 [[C1]]
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;
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%c1 = icmp ugt i32 %x, 42
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%c2 = icmp ne i32 %x, 0
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%res = select i1 %c1, i1 %c2, i1 false
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ret i1 %res
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}
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; Noundef on condition has no effect.
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define i1 @logical_or_noundef_a(i1 noundef %a, i1 %b) {
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; CHECK-LABEL: @logical_or_noundef_a(
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; CHECK-NEXT: [[RES:%.*]] = select i1 [[A:%.*]], i1 true, i1 [[B:%.*]]
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; CHECK-NEXT: ret i1 [[RES]]
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;
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%res = select i1 %a, i1 true, i1 %b
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ret i1 %res
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}
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; Noundef on false value allows conversion to or.
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define i1 @logical_or_noundef_b(i1 %a, i1 noundef %b) {
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; CHECK-LABEL: @logical_or_noundef_b(
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; CHECK-NEXT: [[RES:%.*]] = or i1 [[A:%.*]], [[B:%.*]]
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; CHECK-NEXT: ret i1 [[RES]]
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;
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%res = select i1 %a, i1 true, i1 %b
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ret i1 %res
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}
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; Noundef on condition has no effect.
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define i1 @logical_and_noundef_a(i1 noundef %a, i1 %b) {
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; CHECK-LABEL: @logical_and_noundef_a(
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; CHECK-NEXT: [[RES:%.*]] = select i1 [[A:%.*]], i1 [[B:%.*]], i1 false
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; CHECK-NEXT: ret i1 [[RES]]
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;
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%res = select i1 %a, i1 %b, i1 false
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ret i1 %res
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}
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; Noundef on false value allows conversion to and.
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define i1 @logical_and_noundef_b(i1 %a, i1 noundef %b) {
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; CHECK-LABEL: @logical_and_noundef_b(
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; CHECK-NEXT: [[RES:%.*]] = and i1 [[A:%.*]], [[B:%.*]]
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; CHECK-NEXT: ret i1 [[RES]]
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;
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%res = select i1 %a, i1 %b, i1 false
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ret i1 %res
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}
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