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|
# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
#
# Check that we can fold (x & mask) -> x when (x & mask) is known to equal x.
#
# RUN: llc -mtriple aarch64 -run-pass=aarch64-postlegalizer-combiner -verify-machineinstrs %s -o - | FileCheck %s
---
name: remove_and_with_one_bit
legalized: true
tracksRegLiveness: true
body: |
bb.0:
liveins: $w0, $w1
; G_ICMP produces a single bit. The mask is 1.
;
; cmp = 000...0?
; mask = 000...01
; cmp & mask = 000...0?
;
; Remove the G_AND.
;
; CHECK-LABEL: name: remove_and_with_one_bit
; CHECK: liveins: $w0, $w1
; CHECK: %x:_(s32) = COPY $w0
; CHECK: %y:_(s32) = COPY $w1
; CHECK: %cmp:_(s32) = G_ICMP intpred(eq), %x(s32), %y
; CHECK: $w0 = COPY %cmp(s32)
; CHECK: RET_ReallyLR implicit $w0
%x:_(s32) = COPY $w0
%y:_(s32) = COPY $w1
%cmp:_(s32) = G_ICMP intpred(eq), %x(s32), %y
%mask:_(s32) = G_CONSTANT i32 1
%and:_(s32) = G_AND %cmp(s32), %mask
$w0 = COPY %and(s32)
RET_ReallyLR implicit $w0
...
---
name: remove_and_all_ones_mask
legalized: true
tracksRegLiveness: true
body: |
bb.0:
liveins: $w0, $w1, $w2
; -1 is all ones. Therefore z & -1 = z. Remove the G_AND.
;
; CHECK-LABEL: name: remove_and_all_ones_mask
; CHECK: liveins: $w0, $w1, $w2
; CHECK: %z:_(s32) = COPY $w2
; CHECK: $w0 = COPY %z(s32)
; CHECK: RET_ReallyLR implicit $w0
%x:_(s32) = COPY $w0
%y:_(s32) = COPY $w1
%z:_(s32) = COPY $w2
%mask:_(s32) = G_CONSTANT i32 -1
%and:_(s32) = G_AND %z(s32), %mask
$w0 = COPY %and(s32)
RET_ReallyLR implicit $w0
...
---
name: remove_and_all_ones_zext
legalized: true
tracksRegLiveness: true
body: |
bb.0:
liveins: $w0, $w1, $w2
; %z is a s32, so it can be at most the all-ones value on 32 bits.
; In decimal this is 4294967295. Any zero-extension of %z is at most this
; value.
;
; Therefore, zext(z) & 4294967295 == z. Remove the G_AND.
;
; CHECK-LABEL: name: remove_and_all_ones_zext
; CHECK: liveins: $w0, $w1, $w2
; CHECK: %z:_(s32) = COPY $w2
; CHECK: %ext:_(s64) = G_ZEXT %z(s32)
; CHECK: $x0 = COPY %ext(s64)
; CHECK: RET_ReallyLR implicit $x0
%x:_(s32) = COPY $w0
%y:_(s32) = COPY $w1
%z:_(s32) = COPY $w2
%ext:_(s64) = G_ZEXT %z
%mask:_(s64) = G_CONSTANT i64 4294967295
%and:_(s64) = G_AND %ext(s64), %mask
$x0 = COPY %and(s64)
RET_ReallyLR implicit $x0
...
---
name: remove_and_all_ones_anyext
legalized: true
tracksRegLiveness: true
body: |
bb.0:
liveins: $w0, $w1, $w2
; This is the same as the zext case.
;
; CHECK-LABEL: name: remove_and_all_ones_anyext
; CHECK: liveins: $w0, $w1, $w2
; CHECK: %z:_(s32) = COPY $w2
; CHECK: %ext:_(s64) = G_ZEXT %z(s32)
; CHECK: $x0 = COPY %ext(s64)
; CHECK: RET_ReallyLR implicit $x0
%x:_(s32) = COPY $w0
%y:_(s32) = COPY $w1
%z:_(s32) = COPY $w2
%ext:_(s64) = G_ZEXT %z
%mask:_(s64) = G_CONSTANT i64 4294967295
%and:_(s64) = G_AND %ext(s64), %mask
$x0 = COPY %and(s64)
RET_ReallyLR implicit $x0
...
---
name: dont_remove_all_ones_sext
legalized: true
tracksRegLiveness: true
body: |
bb.0:
liveins: $w0, $w1, $w2
; We don't know if the sign bit is set on %z. So, the value in %ext may have
; higher bits set than 4294967295.
;
; CHECK-LABEL: name: dont_remove_all_ones_sext
; CHECK: liveins: $w0, $w1, $w2
; CHECK: %z:_(s32) = COPY $w2
; CHECK: %ext:_(s64) = G_SEXT %z(s32)
; CHECK: %mask:_(s64) = G_CONSTANT i64 4294967295
; CHECK: %and:_(s64) = G_AND %ext, %mask
; CHECK: $x0 = COPY %and(s64)
; CHECK: RET_ReallyLR implicit $x0
%x:_(s32) = COPY $w0
%y:_(s32) = COPY $w1
%z:_(s32) = COPY $w2
%ext:_(s64) = G_SEXT %z
%mask:_(s64) = G_CONSTANT i64 4294967295
%and:_(s64) = G_AND %ext(s64), %mask
$x0 = COPY %and(s64)
RET_ReallyLR implicit $x0
...
---
name: remove_and_positive_constant_sext
legalized: true
tracksRegLiveness: true
body: |
bb.0:
liveins: $w0, $w1, $w2
; We know the sign bit is not set on %z. Therefore,
;
; z = ext = 42 = 000...0101010
; mask = 0000...0111111
;
; So z & mask == z
; CHECK-LABEL: name: remove_and_positive_constant_sext
; CHECK: liveins: $w0, $w1, $w2
; CHECK: %z:_(s32) = G_CONSTANT i32 42
; CHECK: %ext:_(s64) = G_SEXT %z(s32)
; CHECK: $x0 = COPY %ext(s64)
; CHECK: RET_ReallyLR implicit $x0
%x:_(s32) = COPY $w0
%y:_(s32) = COPY $w1
%z:_(s32) = G_CONSTANT i32 42
%ext:_(s64) = G_SEXT %z
%mask:_(s64) = G_CONSTANT i64 63
%and:_(s64) = G_AND %ext(s64), %mask
$x0 = COPY %and(s64)
RET_ReallyLR implicit $x0
...
---
name: not_a_mask
legalized: true
tracksRegLiveness: true
body: |
bb.0:
liveins: $w0, $w1
; 6 is not a mask, so we should still have the G_AND.
;
; CHECK-LABEL: name: not_a_mask
; CHECK: liveins: $w0, $w1
; CHECK: %x:_(s32) = COPY $w0
; CHECK: %y:_(s32) = COPY $w1
; CHECK: %cmp:_(s32) = G_ICMP intpred(eq), %x(s32), %y
; CHECK: %mask:_(s32) = G_CONSTANT i32 6
; CHECK: %and:_(s32) = G_AND %cmp, %mask
; CHECK: $w0 = COPY %and(s32)
; CHECK: RET_ReallyLR implicit $w0
%x:_(s32) = COPY $w0
%y:_(s32) = COPY $w1
%cmp:_(s32) = G_ICMP intpred(eq), %x(s32), %y
%mask:_(s32) = G_CONSTANT i32 6
%and:_(s32) = G_AND %cmp(s32), %mask
$w0 = COPY %and(s32)
RET_ReallyLR implicit $w0
...
---
name: unknown_val
legalized: true
tracksRegLiveness: true
body: |
bb.0:
liveins: $w0, $w1, $w2
; We don't know what's in $w2, so we can't remove the G_AND without a mask
; that fills every bit in the type.
;
; CHECK-LABEL: name: unknown_val
; CHECK: liveins: $w0, $w1, $w2
; CHECK: %z:_(s32) = COPY $w2
; CHECK: %one:_(s32) = G_CONSTANT i32 32
; CHECK: %and:_(s32) = G_AND %z, %one
; CHECK: $w0 = COPY %and(s32)
; CHECK: RET_ReallyLR implicit $w0
%x:_(s32) = COPY $w0
%y:_(s32) = COPY $w1
%z:_(s32) = COPY $w2
%one:_(s32) = G_CONSTANT i32 32
%and:_(s32) = G_AND %z(s32), %one
$w0 = COPY %and(s32)
RET_ReallyLR implicit $w0
...
---
name: remove_and_assert_zext
legalized: true
tracksRegLiveness: true
body: |
bb.0:
liveins: $w0
; G_ASSERT_ZEXT communicates that only the bottom 8 bits of %x can be set.
; So, the G_AND can be removed.
; CHECK-LABEL: name: remove_and_assert_zext
; CHECK: liveins: $w0
; CHECK: %x:_(s32) = COPY $w0
; CHECK: %assert_zext:_(s32) = G_ASSERT_ZEXT %x, 8
; CHECK: $w0 = COPY %assert_zext(s32)
; CHECK: RET_ReallyLR implicit $w0
%x:_(s32) = COPY $w0
%assert_zext:_(s32) = G_ASSERT_ZEXT %x(s32), 8
%mask:_(s32) = G_CONSTANT i32 255
%and:_(s32) = G_AND %assert_zext(s32), %mask
$w0 = COPY %and(s32)
RET_ReallyLR implicit $w0
...
---
name: dont_remove_and_assert_zext_wrong_mask
legalized: true
tracksRegLiveness: true
body: |
bb.0:
liveins: $w0
; The mask here is for 8 bits, not 16.
; CHECK-LABEL: name: dont_remove_and_assert_zext
; CHECK: liveins: $w0
; CHECK: %x:_(s32) = COPY $w0
; CHECK: %assert_zext:_(s32) = G_ASSERT_ZEXT %x, 16
; CHECK: %mask:_(s32) = G_CONSTANT i32 255
; CHECK: %and:_(s32) = G_AND %assert_zext, %mask
; CHECK: $w0 = COPY %and(s32)
; CHECK: RET_ReallyLR implicit $w0
%x:_(s32) = COPY $w0
%assert_zext:_(s32) = G_ASSERT_ZEXT %x(s32), 16
%mask:_(s32) = G_CONSTANT i32 255
%and:_(s32) = G_AND %assert_zext(s32), %mask
$w0 = COPY %and(s32)
RET_ReallyLR implicit $w0
|
