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[InstCombine] Add test cases to demonstrate that and->xnor and or->xnor folding can create more instructions than it removed when there are multiple uses. NFC 

llvm-svn: 305985
This commit is contained in:
Craig Topper 2017-06-22 05:20:39 +00:00
parent 1d5693c915
commit 71e2c1611e
1 changed files with 50 additions and 0 deletions
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50
llvm/test/Transforms/InstCombine/and-or-not.ll
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@ -1,3 +1,4 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -instcombine -S | FileCheck %s
; PR1510
@ -516,3 +517,52 @@ define i64 @PR32830(i64 %a, i64 %b, i64 %c) {
ret i64 %and
}
; (~a | b) & (~b | a) --> ~(a ^ b)
; TODO: this increases instrunction count if the pieces have additional users
define i32 @and_to_nxor_multiuse(float %fa, float %fb) {
; CHECK-LABEL: @and_to_nxor_multiuse(
; CHECK-NEXT: [[A:%.*]] = fptosi float [[FA:%.*]] to i32
; CHECK-NEXT: [[B:%.*]] = fptosi float [[FB:%.*]] to i32
; CHECK-NEXT: [[NOTA:%.*]] = xor i32 [[A]], -1
; CHECK-NEXT: [[NOTB:%.*]] = xor i32 [[B]], -1
; CHECK-NEXT: [[OR1:%.*]] = or i32 [[NOTA]], [[B]]
; CHECK-NEXT: [[OR2:%.*]] = or i32 [[NOTB]], [[A]]
; CHECK-NEXT: [[TMP1:%.*]] = xor i32 [[B]], [[A]]
; CHECK-NEXT: [[AND:%.*]] = xor i32 [[TMP1]], -1
; CHECK-NEXT: [[MUL1:%.*]] = mul i32 [[OR1]], [[OR2]]
; CHECK-NEXT: [[MUL2:%.*]] = mul i32 [[MUL1]], [[AND]]
; CHECK-NEXT: ret i32 [[MUL2]]
;
%a = fptosi float %fa to i32
%b = fptosi float %fb to i32
%nota = xor i32 %a, -1
%notb = xor i32 %b, -1
%or1 = or i32 %nota, %b
%or2 = or i32 %notb, %a
%and = and i32 %or1, %or2
%mul1 = mul i32 %or1, %or2 ; here to increase the use count of the inputs to the and
%mul2 = mul i32 %mul1, %and
ret i32 %mul2
}
; (a & b) | ~(a | b) --> ~(a ^ b)
; TODO: this increases instrunction count if the pieces have additional users
define i32 @or_to_nxor_multiuse(i32 %a, i32 %b) {
; CHECK-LABEL: @or_to_nxor_multiuse(
; CHECK-NEXT: [[AND:%.*]] = and i32 [[A:%.*]], [[B:%.*]]
; CHECK-NEXT: [[OR:%.*]] = or i32 [[A]], [[B]]
; CHECK-NEXT: [[NOTOR:%.*]] = xor i32 [[OR]], -1
; CHECK-NEXT: [[TMP1:%.*]] = xor i32 [[A]], [[B]]
; CHECK-NEXT: [[OR2:%.*]] = xor i32 [[TMP1]], -1
; CHECK-NEXT: [[MUL1:%.*]] = mul i32 [[AND]], [[NOTOR]]
; CHECK-NEXT: [[MUL2:%.*]] = mul i32 [[MUL1]], [[OR2]]
; CHECK-NEXT: ret i32 [[MUL2]]
;
%and = and i32 %a, %b
%or = or i32 %a, %b
%notor = xor i32 %or, -1
%or2 = or i32 %and, %notor
%mul1 = mul i32 %and, %notor ; here to increase the use count of the inputs to the or
%mul2 = mul i32 %mul1, %or2
ret i32 %mul2
}