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Sanjay Patel 41b5979dcf [InstSimplify] use ConstantRange to simplify or-of-icmps
We can simplify (or (icmp X, C1), (icmp X, C2)) to 'true' or one of the icmps in many cases.
I had to check some of these with Alive to prove to myself it's right, but everything seems 
to check out. Eg, the deleted code in instcombine was completely ignoring predicates with
mismatched signedness.

This is a follow-up to:
https://reviews.llvm.org/rL301260
https://reviews.llvm.org/D32143

llvm-svn: 302370
2017-05-07 15:11:40 +00:00

202 lines
5.7 KiB
LLVM

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -instcombine -S | FileCheck %s
define i1 @PR1817_1(i32 %X) {
; CHECK-LABEL: @PR1817_1(
; CHECK-NEXT: [[B:%.*]] = icmp ult i32 %X, 10
; CHECK-NEXT: ret i1 [[B]]
;
%A = icmp slt i32 %X, 10
%B = icmp ult i32 %X, 10
%C = and i1 %A, %B
ret i1 %C
}
define i1 @PR1817_2(i32 %X) {
; CHECK-LABEL: @PR1817_2(
; CHECK-NEXT: [[A:%.*]] = icmp slt i32 %X, 10
; CHECK-NEXT: ret i1 [[A]]
;
%A = icmp slt i32 %X, 10
%B = icmp ult i32 %X, 10
%C = or i1 %A, %B
ret i1 %C
}
define i1 @PR2330(i32 %a, i32 %b) {
; CHECK-LABEL: @PR2330(
; CHECK-NEXT: [[TMP1:%.*]] = or i32 %b, %a
; CHECK-NEXT: [[TMP2:%.*]] = icmp ult i32 [[TMP1]], 8
; CHECK-NEXT: ret i1 [[TMP2]]
;
%cmp1 = icmp ult i32 %a, 8
%cmp2 = icmp ult i32 %b, 8
%and = and i1 %cmp2, %cmp1
ret i1 %and
}
; if LHSC and RHSC differ only by one bit:
; (X == C1 || X == C2) -> (X | (C1 ^ C2)) == C2
; PR14708: https://bugs.llvm.org/show_bug.cgi?id=14708
define i1 @or_eq_with_one_bit_diff_constants1(i32 %x) {
; CHECK-LABEL: @or_eq_with_one_bit_diff_constants1(
; CHECK-NEXT: [[TMP1:%.*]] = or i32 %x, 1
; CHECK-NEXT: [[TMP2:%.*]] = icmp eq i32 [[TMP1]], 51
; CHECK-NEXT: ret i1 [[TMP2]]
;
%cmp1 = icmp eq i32 %x, 50
%cmp2 = icmp eq i32 %x, 51
%or = or i1 %cmp1, %cmp2
ret i1 %or
}
; (X != C1 && X != C2) -> (X | (C1 ^ C2)) != C2
define i1 @and_ne_with_one_bit_diff_constants1(i32 %x) {
; CHECK-LABEL: @and_ne_with_one_bit_diff_constants1(
; CHECK-NEXT: [[TMP1:%.*]] = or i32 %x, 1
; CHECK-NEXT: [[TMP2:%.*]] = icmp ne i32 [[TMP1]], 51
; CHECK-NEXT: ret i1 [[TMP2]]
;
%cmp1 = icmp ne i32 %x, 51
%cmp2 = icmp ne i32 %x, 50
%and = and i1 %cmp1, %cmp2
ret i1 %and
}
; The constants are not necessarily off-by-one, just off-by-one-bit.
define i1 @or_eq_with_one_bit_diff_constants2(i32 %x) {
; CHECK-LABEL: @or_eq_with_one_bit_diff_constants2(
; CHECK-NEXT: [[TMP1:%.*]] = or i32 %x, 32
; CHECK-NEXT: [[TMP2:%.*]] = icmp eq i32 [[TMP1]], 97
; CHECK-NEXT: ret i1 [[TMP2]]
;
%cmp1 = icmp eq i32 %x, 97
%cmp2 = icmp eq i32 %x, 65
%or = or i1 %cmp1, %cmp2
ret i1 %or
}
define i1 @and_ne_with_one_bit_diff_constants2(i19 %x) {
; CHECK-LABEL: @and_ne_with_one_bit_diff_constants2(
; CHECK-NEXT: [[TMP1:%.*]] = or i19 %x, 128
; CHECK-NEXT: [[TMP2:%.*]] = icmp ne i19 [[TMP1]], 193
; CHECK-NEXT: ret i1 [[TMP2]]
;
%cmp1 = icmp ne i19 %x, 65
%cmp2 = icmp ne i19 %x, 193
%and = and i1 %cmp1, %cmp2
ret i1 %and
}
; Make sure the constants are treated as unsigned when comparing them.
define i1 @or_eq_with_one_bit_diff_constants3(i8 %x) {
; CHECK-LABEL: @or_eq_with_one_bit_diff_constants3(
; CHECK-NEXT: [[TMP1:%.*]] = or i8 %x, -128
; CHECK-NEXT: [[TMP2:%.*]] = icmp eq i8 [[TMP1]], -2
; CHECK-NEXT: ret i1 [[TMP2]]
;
%cmp1 = icmp eq i8 %x, 254
%cmp2 = icmp eq i8 %x, 126
%or = or i1 %cmp1, %cmp2
ret i1 %or
}
define i1 @and_ne_with_one_bit_diff_constants3(i8 %x) {
; CHECK-LABEL: @and_ne_with_one_bit_diff_constants3(
; CHECK-NEXT: [[TMP1:%.*]] = or i8 %x, -128
; CHECK-NEXT: [[TMP2:%.*]] = icmp ne i8 [[TMP1]], -63
; CHECK-NEXT: ret i1 [[TMP2]]
;
%cmp1 = icmp ne i8 %x, 65
%cmp2 = icmp ne i8 %x, 193
%and = and i1 %cmp1, %cmp2
ret i1 %and
}
; Use an 'add' to eliminate an icmp if the constants are off-by-one (not off-by-one-bit).
; (X == 13 | X == 14) -> X-13 <u 2
define i1 @or_eq_with_diff_one(i8 %x) {
; CHECK-LABEL: @or_eq_with_diff_one(
; CHECK-NEXT: [[TMP1:%.*]] = add i8 %x, -13
; CHECK-NEXT: [[TMP2:%.*]] = icmp ult i8 [[TMP1]], 2
; CHECK-NEXT: ret i1 [[TMP2]]
;
%cmp1 = icmp eq i8 %x, 13
%cmp2 = icmp eq i8 %x, 14
%or = or i1 %cmp1, %cmp2
ret i1 %or
}
; (X != 40 | X != 39) -> X-39 >u 1
define i1 @and_ne_with_diff_one(i32 %x) {
; CHECK-LABEL: @and_ne_with_diff_one(
; CHECK-NEXT: [[TMP1:%.*]] = add i32 %x, -39
; CHECK-NEXT: [[TMP2:%.*]] = icmp ugt i32 [[TMP1]], 1
; CHECK-NEXT: ret i1 [[TMP2]]
;
%cmp1 = icmp ne i32 %x, 40
%cmp2 = icmp ne i32 %x, 39
%and = and i1 %cmp1, %cmp2
ret i1 %and
}
; Make sure the constants are treated as signed when comparing them.
; PR32524: https://bugs.llvm.org/show_bug.cgi?id=32524
define i1 @or_eq_with_diff_one_signed(i32 %x) {
; CHECK-LABEL: @or_eq_with_diff_one_signed(
; CHECK-NEXT: [[TMP1:%.*]] = add i32 %x, 1
; CHECK-NEXT: [[TMP2:%.*]] = icmp ult i32 [[TMP1]], 2
; CHECK-NEXT: ret i1 [[TMP2]]
;
%cmp1 = icmp eq i32 %x, 0
%cmp2 = icmp eq i32 %x, -1
%or = or i1 %cmp1, %cmp2
ret i1 %or
}
define i1 @and_ne_with_diff_one_signed(i64 %x) {
; CHECK-LABEL: @and_ne_with_diff_one_signed(
; CHECK-NEXT: [[TMP1:%.*]] = add i64 %x, 1
; CHECK-NEXT: [[TMP2:%.*]] = icmp ugt i64 [[TMP1]], 1
; CHECK-NEXT: ret i1 [[TMP2]]
;
%cmp1 = icmp ne i64 %x, -1
%cmp2 = icmp ne i64 %x, 0
%and = and i1 %cmp1, %cmp2
ret i1 %and
}
; Vectors with splat constants get the same folds.
define <2 x i1> @or_eq_with_one_bit_diff_constants2_splatvec(<2 x i32> %x) {
; CHECK-LABEL: @or_eq_with_one_bit_diff_constants2_splatvec(
; CHECK-NEXT: [[TMP1:%.*]] = or <2 x i32> %x, <i32 32, i32 32>
; CHECK-NEXT: [[TMP2:%.*]] = icmp eq <2 x i32> [[TMP1]], <i32 97, i32 97>
; CHECK-NEXT: ret <2 x i1> [[TMP2]]
;
%cmp1 = icmp eq <2 x i32> %x, <i32 97, i32 97>
%cmp2 = icmp eq <2 x i32> %x, <i32 65, i32 65>
%or = or <2 x i1> %cmp1, %cmp2
ret <2 x i1> %or
}
define <2 x i1> @and_ne_with_diff_one_splatvec(<2 x i32> %x) {
; CHECK-LABEL: @and_ne_with_diff_one_splatvec(
; CHECK-NEXT: [[TMP1:%.*]] = add <2 x i32> %x, <i32 -39, i32 -39>
; CHECK-NEXT: [[TMP2:%.*]] = icmp ugt <2 x i32> [[TMP1]], <i32 1, i32 1>
; CHECK-NEXT: ret <2 x i1> [[TMP2]]
;
%cmp1 = icmp ne <2 x i32> %x, <i32 40, i32 40>
%cmp2 = icmp ne <2 x i32> %x, <i32 39, i32 39>
%and = and <2 x i1> %cmp1, %cmp2
ret <2 x i1> %and
}