llvm-mirror/test/CodeGen/AArch64/arm64-fold-lsl.ll
John Brawn 7a92fa740d [AArch64] Don't reduce the width of loads if it prevents combining a shift
Loads and stores can only shift the offset register by the size of the value
being loaded, but currently the DAGCombiner will reduce the width of the load
if it's followed by a trunc making it impossible to later combine the shift.

Solve this by implementing shouldReduceLoadWidth for the AArch64 backend and
make it prevent the width reduction if this is what would happen, though do
allow it if reducing the load width will let us eliminate a later sign or zero
extend.

Differential Revision: https://reviews.llvm.org/D44794

llvm-svn: 328321
2018-03-23 14:47:07 +00:00

386 lines
12 KiB
LLVM

; RUN: llc < %s -mtriple=arm64-eabi -aarch64-neon-syntax=apple | FileCheck %s
;
; <rdar://problem/14486451>
%struct.a = type [256 x i16]
%struct.b = type [256 x i32]
%struct.c = type [256 x i64]
define i16 @load_halfword(%struct.a* %ctx, i32 %xor72) nounwind {
; CHECK-LABEL: load_halfword:
; CHECK: ubfx [[REG:x[0-9]+]], x1, #9, #8
; CHECK: ldrh w0, [x0, [[REG]], lsl #1]
%shr81 = lshr i32 %xor72, 9
%conv82 = zext i32 %shr81 to i64
%idxprom83 = and i64 %conv82, 255
%arrayidx86 = getelementptr inbounds %struct.a, %struct.a* %ctx, i64 0, i64 %idxprom83
%result = load i16, i16* %arrayidx86, align 2
ret i16 %result
}
define i32 @load_word(%struct.b* %ctx, i32 %xor72) nounwind {
; CHECK-LABEL: load_word:
; CHECK: ubfx [[REG:x[0-9]+]], x1, #9, #8
; CHECK: ldr w0, [x0, [[REG]], lsl #2]
%shr81 = lshr i32 %xor72, 9
%conv82 = zext i32 %shr81 to i64
%idxprom83 = and i64 %conv82, 255
%arrayidx86 = getelementptr inbounds %struct.b, %struct.b* %ctx, i64 0, i64 %idxprom83
%result = load i32, i32* %arrayidx86, align 4
ret i32 %result
}
define i64 @load_doubleword(%struct.c* %ctx, i32 %xor72) nounwind {
; CHECK-LABEL: load_doubleword:
; CHECK: ubfx [[REG:x[0-9]+]], x1, #9, #8
; CHECK: ldr x0, [x0, [[REG]], lsl #3]
%shr81 = lshr i32 %xor72, 9
%conv82 = zext i32 %shr81 to i64
%idxprom83 = and i64 %conv82, 255
%arrayidx86 = getelementptr inbounds %struct.c, %struct.c* %ctx, i64 0, i64 %idxprom83
%result = load i64, i64* %arrayidx86, align 8
ret i64 %result
}
define void @store_halfword(%struct.a* %ctx, i32 %xor72, i16 %val) nounwind {
; CHECK-LABEL: store_halfword:
; CHECK: ubfx [[REG:x[0-9]+]], x1, #9, #8
; CHECK: strh w2, [x0, [[REG]], lsl #1]
%shr81 = lshr i32 %xor72, 9
%conv82 = zext i32 %shr81 to i64
%idxprom83 = and i64 %conv82, 255
%arrayidx86 = getelementptr inbounds %struct.a, %struct.a* %ctx, i64 0, i64 %idxprom83
store i16 %val, i16* %arrayidx86, align 8
ret void
}
define void @store_word(%struct.b* %ctx, i32 %xor72, i32 %val) nounwind {
; CHECK-LABEL: store_word:
; CHECK: ubfx [[REG:x[0-9]+]], x1, #9, #8
; CHECK: str w2, [x0, [[REG]], lsl #2]
%shr81 = lshr i32 %xor72, 9
%conv82 = zext i32 %shr81 to i64
%idxprom83 = and i64 %conv82, 255
%arrayidx86 = getelementptr inbounds %struct.b, %struct.b* %ctx, i64 0, i64 %idxprom83
store i32 %val, i32* %arrayidx86, align 8
ret void
}
define void @store_doubleword(%struct.c* %ctx, i32 %xor72, i64 %val) nounwind {
; CHECK-LABEL: store_doubleword:
; CHECK: ubfx [[REG:x[0-9]+]], x1, #9, #8
; CHECK: str x2, [x0, [[REG]], lsl #3]
%shr81 = lshr i32 %xor72, 9
%conv82 = zext i32 %shr81 to i64
%idxprom83 = and i64 %conv82, 255
%arrayidx86 = getelementptr inbounds %struct.c, %struct.c* %ctx, i64 0, i64 %idxprom83
store i64 %val, i64* %arrayidx86, align 8
ret void
}
; Check that we combine a shift into the offset instead of using a narrower load
; when we have a load followed by a trunc
define i32 @load_doubleword_trunc_word(i64* %ptr, i64 %off) {
; CHECK-LABEL: load_doubleword_trunc_word:
; CHECK: ldr x0, [x0, x1, lsl #3]
entry:
%idx = getelementptr inbounds i64, i64* %ptr, i64 %off
%x = load i64, i64* %idx, align 8
%trunc = trunc i64 %x to i32
ret i32 %trunc
}
define i16 @load_doubleword_trunc_halfword(i64* %ptr, i64 %off) {
; CHECK-LABEL: load_doubleword_trunc_halfword:
; CHECK: ldr x0, [x0, x1, lsl #3]
entry:
%idx = getelementptr inbounds i64, i64* %ptr, i64 %off
%x = load i64, i64* %idx, align 8
%trunc = trunc i64 %x to i16
ret i16 %trunc
}
define i8 @load_doubleword_trunc_byte(i64* %ptr, i64 %off) {
; CHECK-LABEL: load_doubleword_trunc_byte:
; CHECK: ldr x0, [x0, x1, lsl #3]
entry:
%idx = getelementptr inbounds i64, i64* %ptr, i64 %off
%x = load i64, i64* %idx, align 8
%trunc = trunc i64 %x to i8
ret i8 %trunc
}
define i16 @load_word_trunc_halfword(i32* %ptr, i64 %off) {
entry:
; CHECK-LABEL: load_word_trunc_halfword:
; CHECK: ldr w0, [x0, x1, lsl #2]
%idx = getelementptr inbounds i32, i32* %ptr, i64 %off
%x = load i32, i32* %idx, align 8
%trunc = trunc i32 %x to i16
ret i16 %trunc
}
define i8 @load_word_trunc_byte(i32* %ptr, i64 %off) {
; CHECK-LABEL: load_word_trunc_byte:
; CHECK: ldr w0, [x0, x1, lsl #2]
entry:
%idx = getelementptr inbounds i32, i32* %ptr, i64 %off
%x = load i32, i32* %idx, align 8
%trunc = trunc i32 %x to i8
ret i8 %trunc
}
define i8 @load_halfword_trunc_byte(i16* %ptr, i64 %off) {
; CHECK-LABEL: load_halfword_trunc_byte:
; CHECK: ldrh w0, [x0, x1, lsl #1]
entry:
%idx = getelementptr inbounds i16, i16* %ptr, i64 %off
%x = load i16, i16* %idx, align 8
%trunc = trunc i16 %x to i8
ret i8 %trunc
}
; Check that we do use a narrower load, and so don't combine the shift, when
; the loaded value is zero-extended.
define i64 @load_doubleword_trunc_word_zext(i64* %ptr, i64 %off) {
; CHECK-LABEL: load_doubleword_trunc_word_zext:
; CHECK: lsl [[REG:x[0-9]+]], x1, #3
; CHECK: ldr w0, [x0, [[REG]]]
entry:
%idx = getelementptr inbounds i64, i64* %ptr, i64 %off
%x = load i64, i64* %idx, align 8
%trunc = trunc i64 %x to i32
%ext = zext i32 %trunc to i64
ret i64 %ext
}
define i64 @load_doubleword_trunc_halfword_zext(i64* %ptr, i64 %off) {
; CHECK-LABEL: load_doubleword_trunc_halfword_zext:
; CHECK: lsl [[REG:x[0-9]+]], x1, #3
; CHECK: ldrh w0, [x0, [[REG]]]
entry:
%idx = getelementptr inbounds i64, i64* %ptr, i64 %off
%x = load i64, i64* %idx, align 8
%trunc = trunc i64 %x to i16
%ext = zext i16 %trunc to i64
ret i64 %ext
}
define i64 @load_doubleword_trunc_byte_zext(i64* %ptr, i64 %off) {
; CHECK-LABEL: load_doubleword_trunc_byte_zext:
; CHECK: lsl [[REG:x[0-9]+]], x1, #3
; CHECK: ldrb w0, [x0, [[REG]]]
entry:
%idx = getelementptr inbounds i64, i64* %ptr, i64 %off
%x = load i64, i64* %idx, align 8
%trunc = trunc i64 %x to i8
%ext = zext i8 %trunc to i64
ret i64 %ext
}
define i64 @load_word_trunc_halfword_zext(i32* %ptr, i64 %off) {
; CHECK-LABEL: load_word_trunc_halfword_zext:
; CHECK: lsl [[REG:x[0-9]+]], x1, #2
; CHECK: ldrh w0, [x0, [[REG]]]
entry:
%idx = getelementptr inbounds i32, i32* %ptr, i64 %off
%x = load i32, i32* %idx, align 8
%trunc = trunc i32 %x to i16
%ext = zext i16 %trunc to i64
ret i64 %ext
}
define i64 @load_word_trunc_byte_zext(i32* %ptr, i64 %off) {
; CHECK-LABEL: load_word_trunc_byte_zext:
; CHECK: lsl [[REG:x[0-9]+]], x1, #2
; CHECK: ldrb w0, [x0, [[REG]]]
entry:
%idx = getelementptr inbounds i32, i32* %ptr, i64 %off
%x = load i32, i32* %idx, align 8
%trunc = trunc i32 %x to i8
%ext = zext i8 %trunc to i64
ret i64 %ext
}
define i64 @load_halfword_trunc_byte_zext(i16* %ptr, i64 %off) {
; CHECK-LABEL: load_halfword_trunc_byte_zext:
; CHECK: lsl [[REG:x[0-9]+]], x1, #1
; CHECK: ldrb w0, [x0, [[REG]]]
entry:
%idx = getelementptr inbounds i16, i16* %ptr, i64 %off
%x = load i16, i16* %idx, align 8
%trunc = trunc i16 %x to i8
%ext = zext i8 %trunc to i64
ret i64 %ext
}
; Check that we do use a narrower load, and so don't combine the shift, when
; the loaded value is sign-extended.
define i64 @load_doubleword_trunc_word_sext(i64* %ptr, i64 %off) {
; CHECK-LABEL: load_doubleword_trunc_word_sext:
; CHECK: lsl [[REG:x[0-9]+]], x1, #3
; CHECK: ldrsw x0, [x0, [[REG]]]
entry:
%idx = getelementptr inbounds i64, i64* %ptr, i64 %off
%x = load i64, i64* %idx, align 8
%trunc = trunc i64 %x to i32
%ext = sext i32 %trunc to i64
ret i64 %ext
}
define i64 @load_doubleword_trunc_halfword_sext(i64* %ptr, i64 %off) {
; CHECK-LABEL: load_doubleword_trunc_halfword_sext:
; CHECK: lsl [[REG:x[0-9]+]], x1, #3
; CHECK: ldrsh x0, [x0, [[REG]]]
entry:
%idx = getelementptr inbounds i64, i64* %ptr, i64 %off
%x = load i64, i64* %idx, align 8
%trunc = trunc i64 %x to i16
%ext = sext i16 %trunc to i64
ret i64 %ext
}
define i64 @load_doubleword_trunc_byte_sext(i64* %ptr, i64 %off) {
; CHECK-LABEL: load_doubleword_trunc_byte_sext:
; CHECK: lsl [[REG:x[0-9]+]], x1, #3
; CHECK: ldrsb x0, [x0, [[REG]]]
entry:
%idx = getelementptr inbounds i64, i64* %ptr, i64 %off
%x = load i64, i64* %idx, align 8
%trunc = trunc i64 %x to i8
%ext = sext i8 %trunc to i64
ret i64 %ext
}
define i64 @load_word_trunc_halfword_sext(i32* %ptr, i64 %off) {
; CHECK-LABEL: load_word_trunc_halfword_sext:
; CHECK: lsl [[REG:x[0-9]+]], x1, #2
; CHECK: ldrsh x0, [x0, [[REG]]]
entry:
%idx = getelementptr inbounds i32, i32* %ptr, i64 %off
%x = load i32, i32* %idx, align 8
%trunc = trunc i32 %x to i16
%ext = sext i16 %trunc to i64
ret i64 %ext
}
define i64 @load_word_trunc_byte_sext(i32* %ptr, i64 %off) {
; CHECK-LABEL: load_word_trunc_byte_sext:
; CHECK: lsl [[REG:x[0-9]+]], x1, #2
; CHECK: ldrsb x0, [x0, [[REG]]]
entry:
%idx = getelementptr inbounds i32, i32* %ptr, i64 %off
%x = load i32, i32* %idx, align 8
%trunc = trunc i32 %x to i8
%ext = sext i8 %trunc to i64
ret i64 %ext
}
define i64 @load_halfword_trunc_byte_sext(i16* %ptr, i64 %off) {
; CHECK-LABEL: load_halfword_trunc_byte_sext:
; CHECK: lsl [[REG:x[0-9]+]], x1, #1
; CHECK: ldrsb x0, [x0, [[REG]]]
entry:
%idx = getelementptr inbounds i16, i16* %ptr, i64 %off
%x = load i16, i16* %idx, align 8
%trunc = trunc i16 %x to i8
%ext = sext i8 %trunc to i64
ret i64 %ext
}
; Check that we don't combine the shift, and so will use a narrower load, when
; the shift is used more than once.
define i32 @load_doubleword_trunc_word_reuse_shift(i64* %ptr, i64 %off) {
; CHECK-LABEL: load_doubleword_trunc_word_reuse_shift:
; CHECK: lsl x[[REG1:[0-9]+]], x1, #3
; CHECK: ldr w[[REG2:[0-9]+]], [x0, x[[REG1]]]
; CHECL: add w0, w[[REG2]], w[[REG1]]
entry:
%idx = getelementptr inbounds i64, i64* %ptr, i64 %off
%x = load i64, i64* %idx, align 8
%trunc = trunc i64 %x to i32
%lsl = shl i64 %off, 3
%lsl.trunc = trunc i64 %lsl to i32
%add = add i32 %trunc, %lsl.trunc
ret i32 %add
}
define i16 @load_doubleword_trunc_halfword_reuse_shift(i64* %ptr, i64 %off) {
; CHECK-LABEL: load_doubleword_trunc_halfword_reuse_shift:
; CHECK: lsl x[[REG1:[0-9]+]], x1, #3
; CHECK: ldrh w[[REG2:[0-9]+]], [x0, x[[REG1]]]
; CHECK: add w0, w[[REG2]], w[[REG1]]
entry:
%idx = getelementptr inbounds i64, i64* %ptr, i64 %off
%x = load i64, i64* %idx, align 8
%trunc = trunc i64 %x to i16
%lsl = shl i64 %off, 3
%lsl.trunc = trunc i64 %lsl to i16
%add = add i16 %trunc, %lsl.trunc
ret i16 %add
}
define i8 @load_doubleword_trunc_byte_reuse_shift(i64* %ptr, i64 %off) {
; CHECK-LABEL: load_doubleword_trunc_byte_reuse_shift:
; CHECK: lsl x[[REG1:[0-9]+]], x1, #3
; CHECK: ldrb w[[REG2:[0-9]+]], [x0, x[[REG1]]]
; CHECK: add w0, w[[REG2]], w[[REG1]]
entry:
%idx = getelementptr inbounds i64, i64* %ptr, i64 %off
%x = load i64, i64* %idx, align 8
%trunc = trunc i64 %x to i8
%lsl = shl i64 %off, 3
%lsl.trunc = trunc i64 %lsl to i8
%add = add i8 %trunc, %lsl.trunc
ret i8 %add
}
define i16 @load_word_trunc_halfword_reuse_shift(i32* %ptr, i64 %off) {
entry:
; CHECK-LABEL: load_word_trunc_halfword_reuse_shift:
; CHECK: lsl x[[REG1:[0-9]+]], x1, #2
; CHECK: ldrh w[[REG2:[0-9]+]], [x0, x[[REG1]]]
; CHECK: add w0, w[[REG2]], w[[REG1]]
%idx = getelementptr inbounds i32, i32* %ptr, i64 %off
%x = load i32, i32* %idx, align 8
%trunc = trunc i32 %x to i16
%lsl = shl i64 %off, 2
%lsl.trunc = trunc i64 %lsl to i16
%add = add i16 %trunc, %lsl.trunc
ret i16 %add
}
define i8 @load_word_trunc_byte_reuse_shift(i32* %ptr, i64 %off) {
; CHECK-LABEL: load_word_trunc_byte_reuse_shift:
; CHECK: lsl x[[REG1:[0-9]+]], x1, #2
; CHECK: ldrb w[[REG2:[0-9]+]], [x0, x[[REG1]]]
; CHECK: add w0, w[[REG2]], w[[REG1]]
entry:
%idx = getelementptr inbounds i32, i32* %ptr, i64 %off
%x = load i32, i32* %idx, align 8
%trunc = trunc i32 %x to i8
%lsl = shl i64 %off, 2
%lsl.trunc = trunc i64 %lsl to i8
%add = add i8 %trunc, %lsl.trunc
ret i8 %add
}
define i8 @load_halfword_trunc_byte_reuse_shift(i16* %ptr, i64 %off) {
; CHECK-LABEL: load_halfword_trunc_byte_reuse_shift:
; CHECK: lsl x[[REG1:[0-9]+]], x1, #1
; CHECK: ldrb w[[REG2:[0-9]+]], [x0, x[[REG1]]]
; CHECK: add w0, w[[REG2]], w[[REG1]]
entry:
%idx = getelementptr inbounds i16, i16* %ptr, i64 %off
%x = load i16, i16* %idx, align 8
%trunc = trunc i16 %x to i8
%lsl = shl i64 %off, 1
%lsl.trunc = trunc i64 %lsl to i8
%add = add i8 %trunc, %lsl.trunc
ret i8 %add
}