llvm-6502/test/CodeGen/AArch64/and-mask-removal.ll
Louis Gerbarg 6393b3a677 Remove spurious mask operations from AArch64 add->compares on 16 and 8 bit values
This patch checks for DAG patterns that are an add or a sub followed by a
compare on 16 and 8 bit inputs. Since AArch64 does not support those types
natively they are legalized into 32 bit values, which means that mask operations
are inserted into the DAG to emulate overflow behaviour. In many cases those
masks do not change the result of the processing and just introduce a dependent
operation, often in the middle of a hot loop.

This patch detects the relevent DAG patterns and then tests to see if the
transforms are equivalent with and without the mask, removing the mask if
possible. The exact mechanism of this patch was discusses in
http://lists.cs.uiuc.edu/pipermail/llvmdev/2014-July/074444.html

There is a reasonably good chance there are missed oppurtunities due to similiar
(but not identical) DAG patterns that could be funneled into this test, adding
them should be simple if we see test cases.

Tests included.

rdar://13754426

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216776 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-29 21:00:22 +00:00

270 lines
5.4 KiB
LLVM

; RUN: llc -O0 -fast-isel=false -mtriple=arm64-apple-darwin < %s | FileCheck %s
@board = common global [400 x i8] zeroinitializer, align 1
@next_string = common global i32 0, align 4
@string_number = common global [400 x i32] zeroinitializer, align 4
; Function Attrs: nounwind ssp
define void @new_position(i32 %pos) {
entry:
%idxprom = sext i32 %pos to i64
%arrayidx = getelementptr inbounds [400 x i8]* @board, i64 0, i64 %idxprom
%tmp = load i8* %arrayidx, align 1
%.off = add i8 %tmp, -1
%switch = icmp ult i8 %.off, 2
br i1 %switch, label %if.then, label %if.end
if.then: ; preds = %entry
%tmp1 = load i32* @next_string, align 4
%arrayidx8 = getelementptr inbounds [400 x i32]* @string_number, i64 0, i64 %idxprom
store i32 %tmp1, i32* %arrayidx8, align 4
br label %if.end
if.end: ; preds = %if.then, %entry
ret void
; CHECK-LABEL: new_position
; CHECK-NOT: and
; CHECK: ret
}
define zeroext i1 @test8_0(i8 zeroext %x) align 2 {
entry:
%0 = add i8 %x, 74
%1 = icmp ult i8 %0, -20
br i1 %1, label %ret_true, label %ret_false
ret_false:
ret i1 false
ret_true:
ret i1 true
; CHECK-LABEL: test8_0
; CHECK: and
; CHECK: ret
}
define zeroext i1 @test8_1(i8 zeroext %x) align 2 {
entry:
%0 = add i8 %x, 246
%1 = icmp uge i8 %0, 90
br i1 %1, label %ret_true, label %ret_false
ret_false:
ret i1 false
ret_true:
ret i1 true
; CHECK-LABEL: test8_1
; CHECK-NOT: and
; CHECK: ret
}
define zeroext i1 @test8_2(i8 zeroext %x) align 2 {
entry:
%0 = add i8 %x, 227
%1 = icmp ne i8 %0, 179
br i1 %1, label %ret_true, label %ret_false
ret_false:
ret i1 false
ret_true:
ret i1 true
; CHECK-LABEL: test8_2
; CHECK-NOT: and
; CHECK: ret
}
define zeroext i1 @test8_3(i8 zeroext %x) align 2 {
entry:
%0 = add i8 %x, 201
%1 = icmp eq i8 %0, 154
br i1 %1, label %ret_true, label %ret_false
ret_false:
ret i1 false
ret_true:
ret i1 true
; CHECK-LABEL: test8_3
; CHECK-NOT: and
; CHECK: ret
}
define zeroext i1 @test8_4(i8 zeroext %x) align 2 {
entry:
%0 = add i8 %x, -79
%1 = icmp ne i8 %0, -40
br i1 %1, label %ret_true, label %ret_false
ret_false:
ret i1 false
ret_true:
ret i1 true
; CHECK-LABEL: test8_4
; CHECK-NOT: and
; CHECK: ret
}
define zeroext i1 @test8_5(i8 zeroext %x) align 2 {
entry:
%0 = add i8 %x, 133
%1 = icmp uge i8 %0, -105
br i1 %1, label %ret_true, label %ret_false
ret_false:
ret i1 false
ret_true:
ret i1 true
; CHECK-LABEL: test8_5
; CHECK: and
; CHECK: ret
}
define zeroext i1 @test8_6(i8 zeroext %x) align 2 {
entry:
%0 = add i8 %x, -58
%1 = icmp uge i8 %0, 155
br i1 %1, label %ret_true, label %ret_false
ret_false:
ret i1 false
ret_true:
ret i1 true
; CHECK-LABEL: test8_6
; CHECK: and
; CHECK: ret
}
define zeroext i1 @test8_7(i8 zeroext %x) align 2 {
entry:
%0 = add i8 %x, 225
%1 = icmp ult i8 %0, 124
br i1 %1, label %ret_true, label %ret_false
ret_false:
ret i1 false
ret_true:
ret i1 true
; CHECK-LABEL: test8_7
; CHECK-NOT: and
; CHECK: ret
}
define zeroext i1 @test8_8(i8 zeroext %x) align 2 {
entry:
%0 = add i8 %x, 190
%1 = icmp uge i8 %0, 1
br i1 %1, label %ret_true, label %ret_false
ret_false:
ret i1 false
ret_true:
ret i1 true
; CHECK-LABEL: test8_8
; CHECK-NOT: and
; CHECK: ret
}
define zeroext i1 @test16_0(i16 zeroext %x) align 2 {
entry:
%0 = add i16 %x, -46989
%1 = icmp ne i16 %0, -41903
br i1 %1, label %ret_true, label %ret_false
ret_false:
ret i1 false
ret_true:
ret i1 true
; CHECK-LABEL: test16_0
; CHECK-NOT: and
; CHECK: ret
}
define zeroext i1 @test16_2(i16 zeroext %x) align 2 {
entry:
%0 = add i16 %x, 16882
%1 = icmp ule i16 %0, -24837
br i1 %1, label %ret_true, label %ret_false
ret_false:
ret i1 false
ret_true:
ret i1 true
; CHECK-LABEL: test16_2
; CHECK: and
; CHECK: ret
}
define zeroext i1 @test16_3(i16 zeroext %x) align 2 {
entry:
%0 = add i16 %x, 29283
%1 = icmp ne i16 %0, 16947
br i1 %1, label %ret_true, label %ret_false
ret_false:
ret i1 false
ret_true:
ret i1 true
; CHECK-LABEL: test16_3
; CHECK-NOT: and
; CHECK: ret
}
define zeroext i1 @test16_4(i16 zeroext %x) align 2 {
entry:
%0 = add i16 %x, -35551
%1 = icmp uge i16 %0, 15677
br i1 %1, label %ret_true, label %ret_false
ret_false:
ret i1 false
ret_true:
ret i1 true
; CHECK-LABEL: test16_4
; CHECK: and
; CHECK: ret
}
define zeroext i1 @test16_5(i16 zeroext %x) align 2 {
entry:
%0 = add i16 %x, -25214
%1 = icmp ne i16 %0, -1932
br i1 %1, label %ret_true, label %ret_false
ret_false:
ret i1 false
ret_true:
ret i1 true
; CHECK-LABEL: test16_5
; CHECK-NOT: and
; CHECK: ret
}
define zeroext i1 @test16_6(i16 zeroext %x) align 2 {
entry:
%0 = add i16 %x, -32194
%1 = icmp uge i16 %0, -41215
br i1 %1, label %ret_true, label %ret_false
ret_false:
ret i1 false
ret_true:
ret i1 true
; CHECK-LABEL: test16_6
; CHECK-NOT: and
; CHECK: ret
}
define zeroext i1 @test16_7(i16 zeroext %x) align 2 {
entry:
%0 = add i16 %x, 9272
%1 = icmp uge i16 %0, -42916
br i1 %1, label %ret_true, label %ret_false
ret_false:
ret i1 false
ret_true:
ret i1 true
; CHECK-LABEL: test16_7
; CHECK: and
; CHECK: ret
}
define zeroext i1 @test16_8(i16 zeroext %x) align 2 {
entry:
%0 = add i16 %x, -63749
%1 = icmp ne i16 %0, 6706
br i1 %1, label %ret_true, label %ret_false
ret_false:
ret i1 false
ret_true:
ret i1 true
; CHECK-LABEL: test16_8
; CHECK-NOT: and
; CHECK: ret
}