[llvm] r301802 - [InstCombine] add multi-use variants for DeMorgan folds; NFC
Sanjay Patel via llvm-commits
llvm-commits at lists.llvm.org
Mon May 1 07:52:17 PDT 2017
Author: spatel
Date: Mon May 1 09:52:17 2017
New Revision: 301802
URL: http://llvm.org/viewvc/llvm-project?rev=301802&view=rev
Log:
[InstCombine] add multi-use variants for DeMorgan folds; NFC
Modified:
llvm/trunk/test/Transforms/InstCombine/demorgan.ll
Modified: llvm/trunk/test/Transforms/InstCombine/demorgan.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/demorgan.ll?rev=301802&r1=301801&r2=301802&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/demorgan.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/demorgan.ll Mon May 1 09:52:17 2017
@@ -242,6 +242,134 @@ define i8 @demorgan_nor(i8 %A, i8 %B) {
ret i8 %notc
}
+; ~(~A | B) --> (A & ~B) - what if we use one of the intermediate results?
+
+define i8 @demorgan_nor_use2a(i8 %A, i8 %B) {
+; CHECK-LABEL: @demorgan_nor_use2a(
+; CHECK-NEXT: [[NOTA:%.*]] = xor i8 %A, -1
+; CHECK-NEXT: [[USE2A:%.*]] = mul i8 [[NOTA]], 23
+; CHECK-NEXT: [[B_NOT:%.*]] = xor i8 %B, -1
+; CHECK-NEXT: [[NOTC:%.*]] = and i8 [[B_NOT]], %A
+; CHECK-NEXT: [[R:%.*]] = sdiv i8 [[NOTC]], [[USE2A]]
+; CHECK-NEXT: ret i8 [[R]]
+;
+ %nota = xor i8 %A, -1
+ %use2a = mul i8 %nota, 23
+ %c = or i8 %nota, %B
+ %notc = xor i8 %c, -1
+ %r = sdiv i8 %notc, %use2a
+ ret i8 %r
+}
+
+; ~(~A | B) --> (A & ~B) - what if we use one of the intermediate results?
+
+define i8 @demorgan_nor_use2b(i8 %A, i8 %B) {
+; CHECK-LABEL: @demorgan_nor_use2b(
+; CHECK-NEXT: [[USE2B:%.*]] = mul i8 %B, 23
+; CHECK-NEXT: [[B_NOT:%.*]] = xor i8 %B, -1
+; CHECK-NEXT: [[NOTC:%.*]] = and i8 [[B_NOT]], %A
+; CHECK-NEXT: [[R:%.*]] = sdiv i8 [[NOTC]], [[USE2B]]
+; CHECK-NEXT: ret i8 [[R]]
+;
+ %use2b = mul i8 %B, 23
+ %nota = xor i8 %A, -1
+ %c = or i8 %nota, %B
+ %notc = xor i8 %c, -1
+ %r = sdiv i8 %notc, %use2b
+ ret i8 %r
+}
+
+; ~(~A | B) --> (A & ~B) - what if we use one of the intermediate results?
+
+define i8 @demorgan_nor_use2c(i8 %A, i8 %B) {
+; CHECK-LABEL: @demorgan_nor_use2c(
+; CHECK-NEXT: [[NOTA:%.*]] = xor i8 %A, -1
+; CHECK-NEXT: [[C:%.*]] = or i8 [[NOTA]], %B
+; CHECK-NEXT: [[USE2C:%.*]] = mul i8 [[C]], 23
+; CHECK-NEXT: [[B_NOT:%.*]] = xor i8 %B, -1
+; CHECK-NEXT: [[NOTC:%.*]] = and i8 [[B_NOT]], %A
+; CHECK-NEXT: [[R:%.*]] = sdiv i8 [[NOTC]], [[USE2C]]
+; CHECK-NEXT: ret i8 [[R]]
+;
+ %nota = xor i8 %A, -1
+ %c = or i8 %nota, %B
+ %use2c = mul i8 %c, 23
+ %notc = xor i8 %c, -1
+ %r = sdiv i8 %notc, %use2c
+ ret i8 %r
+}
+
+; ~(~A | B) --> (A & ~B) - what if we use two of the intermediate results?
+
+define i8 @demorgan_nor_use2ab(i8 %A, i8 %B) {
+; CHECK-LABEL: @demorgan_nor_use2ab(
+; CHECK-NEXT: [[USE2B:%.*]] = mul i8 %B, 23
+; CHECK-NEXT: [[NOTA:%.*]] = xor i8 %A, -1
+; CHECK-NEXT: [[USE2A:%.*]] = mul i8 [[NOTA]], 17
+; CHECK-NEXT: [[B_NOT:%.*]] = xor i8 %B, -1
+; CHECK-NEXT: [[NOTC:%.*]] = and i8 [[B_NOT]], %A
+; CHECK-NEXT: [[R1:%.*]] = sdiv i8 [[NOTC]], [[USE2B]]
+; CHECK-NEXT: [[R2:%.*]] = sdiv i8 [[R1]], [[USE2A]]
+; CHECK-NEXT: ret i8 [[R2]]
+;
+ %use2b = mul i8 %B, 23
+ %nota = xor i8 %A, -1
+ %use2a = mul i8 %nota, 17
+ %c = or i8 %nota, %B
+ %notc = xor i8 %c, -1
+ %r1 = sdiv i8 %notc, %use2b
+ %r2 = sdiv i8 %r1, %use2a
+ ret i8 %r2
+}
+
+; ~(~A | B) --> (A & ~B) - what if we use two of the intermediate results?
+
+define i8 @demorgan_nor_use2ac(i8 %A, i8 %B) {
+; CHECK-LABEL: @demorgan_nor_use2ac(
+; CHECK-NEXT: [[NOTA:%.*]] = xor i8 %A, -1
+; CHECK-NEXT: [[USE2A:%.*]] = mul i8 [[NOTA]], 17
+; CHECK-NEXT: [[C:%.*]] = or i8 [[NOTA]], %B
+; CHECK-NEXT: [[USE2C:%.*]] = mul i8 [[C]], 23
+; CHECK-NEXT: [[B_NOT:%.*]] = xor i8 %B, -1
+; CHECK-NEXT: [[NOTC:%.*]] = and i8 [[B_NOT]], %A
+; CHECK-NEXT: [[R1:%.*]] = sdiv i8 [[NOTC]], [[USE2C]]
+; CHECK-NEXT: [[R2:%.*]] = sdiv i8 [[R1]], [[USE2A]]
+; CHECK-NEXT: ret i8 [[R2]]
+;
+ %nota = xor i8 %A, -1
+ %use2a = mul i8 %nota, 17
+ %c = or i8 %nota, %B
+ %use2c = mul i8 %c, 23
+ %notc = xor i8 %c, -1
+ %r1 = sdiv i8 %notc, %use2c
+ %r2 = sdiv i8 %r1, %use2a
+ ret i8 %r2
+}
+
+; ~(~A | B) --> (A & ~B) - what if we use two of the intermediate results?
+
+define i8 @demorgan_nor_use2bc(i8 %A, i8 %B) {
+; CHECK-LABEL: @demorgan_nor_use2bc(
+; CHECK-NEXT: [[USE2B:%.*]] = mul i8 %B, 23
+; CHECK-NEXT: [[NOTA:%.*]] = xor i8 %A, -1
+; CHECK-NEXT: [[C:%.*]] = or i8 [[NOTA]], %B
+; CHECK-NEXT: [[USE2C:%.*]] = mul i8 [[C]], 23
+; CHECK-NEXT: [[B_NOT:%.*]] = xor i8 %B, -1
+; CHECK-NEXT: [[NOTC:%.*]] = and i8 [[B_NOT]], %A
+; CHECK-NEXT: [[R1:%.*]] = sdiv i8 [[NOTC]], [[USE2C]]
+; CHECK-NEXT: [[R2:%.*]] = sdiv i8 [[R1]], [[USE2B]]
+; CHECK-NEXT: ret i8 [[R2]]
+;
+ %use2b = mul i8 %B, 23
+ %nota = xor i8 %A, -1
+ %c = or i8 %nota, %B
+ %use2c = mul i8 %c, 23
+ %notc = xor i8 %c, -1
+ %r1 = sdiv i8 %notc, %use2c
+ %r2 = sdiv i8 %r1, %use2b
+ ret i8 %r2
+}
+
; FIXME: Do not apply DeMorgan's Law to constants. We prefer 'not' ops.
define i32 @demorganize_constant1(i32 %a) {
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