1
0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2025-01-31 20:51:52 +01:00
llvm-mirror/test/CodeGen/X86/dagcombine-shifts.ll
Craig Topper 9d88bde411 [X86FixupLEAs] Turn optIncDec into a generic two address LEA optimizer. Support LEA64_32r properly.
INC/DEC is really a special case of a more generic issue. We should also turn leas into add reg/reg or add reg/imm regardless of the slow lea flags.

This also supports LEA64_32 which has 64 bit input registers and 32 bit output registers. So we need to convert the 64 bit inputs to their 32 bit equivalents to check if they are equal to base reg.

One thing to note, the original code preserved the kill flags by adding operands to the new instruction instead of using addReg. But I think tied operands aren't supposed to have the kill flag set. I dropped the kill flags, but I could probably try to preserve it in the add reg/reg case if we think its important. Not sure which operand its supposed to go on for the LEA64_32r instruction due to the super reg implicit uses. Though I'm also not sure those are needed since they were probably just created by an INSERT_SUBREG from a 32-bit input.

Differential Revision: https://reviews.llvm.org/D61472

llvm-svn: 361691
2019-05-25 06:17:47 +00:00

218 lines
5.4 KiB
LLVM

; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc < %s -mtriple=x86_64-linux-gnu | FileCheck %s
; fold (shl (zext (lshr (A, X))), X) -> (zext (shl (lshr (A, X)), X))
; Canolicalize the sequence shl/zext/lshr performing the zeroextend
; as the last instruction of the sequence.
; This will help DAGCombiner to identify and then fold the sequence
; of shifts into a single AND.
; This transformation is profitable if the shift amounts are the same
; and if there is only one use of the zext.
define i16 @fun1(i8 zeroext %v) {
; CHECK-LABEL: fun1:
; CHECK: # %bb.0: # %entry
; CHECK-NEXT: movl %edi, %eax
; CHECK-NEXT: andl $-16, %eax
; CHECK-NEXT: # kill: def $ax killed $ax killed $eax
; CHECK-NEXT: retq
entry:
%shr = lshr i8 %v, 4
%ext = zext i8 %shr to i16
%shl = shl i16 %ext, 4
ret i16 %shl
}
define i32 @fun2(i8 zeroext %v) {
; CHECK-LABEL: fun2:
; CHECK: # %bb.0: # %entry
; CHECK-NEXT: movl %edi, %eax
; CHECK-NEXT: andl $-16, %eax
; CHECK-NEXT: retq
entry:
%shr = lshr i8 %v, 4
%ext = zext i8 %shr to i32
%shl = shl i32 %ext, 4
ret i32 %shl
}
define i32 @fun3(i16 zeroext %v) {
; CHECK-LABEL: fun3:
; CHECK: # %bb.0: # %entry
; CHECK-NEXT: movl %edi, %eax
; CHECK-NEXT: andl $-16, %eax
; CHECK-NEXT: retq
entry:
%shr = lshr i16 %v, 4
%ext = zext i16 %shr to i32
%shl = shl i32 %ext, 4
ret i32 %shl
}
define i64 @fun4(i8 zeroext %v) {
; CHECK-LABEL: fun4:
; CHECK: # %bb.0: # %entry
; CHECK-NEXT: movl %edi, %eax
; CHECK-NEXT: andl $-16, %eax
; CHECK-NEXT: retq
entry:
%shr = lshr i8 %v, 4
%ext = zext i8 %shr to i64
%shl = shl i64 %ext, 4
ret i64 %shl
}
define i64 @fun5(i16 zeroext %v) {
; CHECK-LABEL: fun5:
; CHECK: # %bb.0: # %entry
; CHECK-NEXT: movl %edi, %eax
; CHECK-NEXT: andl $-16, %eax
; CHECK-NEXT: retq
entry:
%shr = lshr i16 %v, 4
%ext = zext i16 %shr to i64
%shl = shl i64 %ext, 4
ret i64 %shl
}
define i64 @fun6(i32 zeroext %v) {
; CHECK-LABEL: fun6:
; CHECK: # %bb.0: # %entry
; CHECK-NEXT: movl %edi, %eax
; CHECK-NEXT: andl $-16, %eax
; CHECK-NEXT: retq
entry:
%shr = lshr i32 %v, 4
%ext = zext i32 %shr to i64
%shl = shl i64 %ext, 4
ret i64 %shl
}
; Don't fold the pattern if we use arithmetic shifts.
define i64 @fun7(i8 zeroext %v) {
; CHECK-LABEL: fun7:
; CHECK: # %bb.0: # %entry
; CHECK-NEXT: sarb $4, %dil
; CHECK-NEXT: movzbl %dil, %eax
; CHECK-NEXT: shlq $4, %rax
; CHECK-NEXT: retq
entry:
%shr = ashr i8 %v, 4
%ext = zext i8 %shr to i64
%shl = shl i64 %ext, 4
ret i64 %shl
}
define i64 @fun8(i16 zeroext %v) {
; CHECK-LABEL: fun8:
; CHECK: # %bb.0: # %entry
; CHECK-NEXT: movswl %di, %eax
; CHECK-NEXT: shrl $4, %eax
; CHECK-NEXT: movzwl %ax, %eax
; CHECK-NEXT: shlq $4, %rax
; CHECK-NEXT: retq
entry:
%shr = ashr i16 %v, 4
%ext = zext i16 %shr to i64
%shl = shl i64 %ext, 4
ret i64 %shl
}
define i64 @fun9(i32 zeroext %v) {
; CHECK-LABEL: fun9:
; CHECK: # %bb.0: # %entry
; CHECK-NEXT: movl %edi, %eax
; CHECK-NEXT: sarl $4, %eax
; CHECK-NEXT: shlq $4, %rax
; CHECK-NEXT: retq
entry:
%shr = ashr i32 %v, 4
%ext = zext i32 %shr to i64
%shl = shl i64 %ext, 4
ret i64 %shl
}
; Don't fold the pattern if there is more than one use of the
; operand in input to the shift left.
define i64 @fun10(i8 zeroext %v) {
; CHECK-LABEL: fun10:
; CHECK: # %bb.0: # %entry
; CHECK-NEXT: shrb $4, %dil
; CHECK-NEXT: movzbl %dil, %ecx
; CHECK-NEXT: movq %rcx, %rax
; CHECK-NEXT: shlq $4, %rax
; CHECK-NEXT: orq %rcx, %rax
; CHECK-NEXT: retq
entry:
%shr = lshr i8 %v, 4
%ext = zext i8 %shr to i64
%shl = shl i64 %ext, 4
%add = add i64 %shl, %ext
ret i64 %add
}
define i64 @fun11(i16 zeroext %v) {
; CHECK-LABEL: fun11:
; CHECK: # %bb.0: # %entry
; CHECK-NEXT: # kill: def $edi killed $edi def $rdi
; CHECK-NEXT: shrl $4, %edi
; CHECK-NEXT: movq %rdi, %rax
; CHECK-NEXT: shlq $4, %rax
; CHECK-NEXT: addq %rdi, %rax
; CHECK-NEXT: retq
entry:
%shr = lshr i16 %v, 4
%ext = zext i16 %shr to i64
%shl = shl i64 %ext, 4
%add = add i64 %shl, %ext
ret i64 %add
}
define i64 @fun12(i32 zeroext %v) {
; CHECK-LABEL: fun12:
; CHECK: # %bb.0: # %entry
; CHECK-NEXT: # kill: def $edi killed $edi def $rdi
; CHECK-NEXT: shrl $4, %edi
; CHECK-NEXT: movq %rdi, %rax
; CHECK-NEXT: shlq $4, %rax
; CHECK-NEXT: addq %rdi, %rax
; CHECK-NEXT: retq
entry:
%shr = lshr i32 %v, 4
%ext = zext i32 %shr to i64
%shl = shl i64 %ext, 4
%add = add i64 %shl, %ext
ret i64 %add
}
; PR17380
; Make sure that the combined dags are legal if we run the DAGCombiner after
; Legalization took place. The add instruction is redundant and increases by
; one the number of uses of the zext. This prevents the transformation from
; firing before dags are legalized and optimized.
; Once the add is removed, the number of uses becomes one and therefore the
; dags are canonicalized. After Legalization, we need to make sure that the
; valuetype for the shift count is legal.
; Verify also that we correctly fold the shl-shr sequence into an
; AND with bitmask.
define void @g(i32 %a) {
; CHECK-LABEL: g:
; CHECK: # %bb.0:
; CHECK-NEXT: # kill: def $edi killed $edi def $rdi
; CHECK-NEXT: andl $-4, %edi
; CHECK-NEXT: jmp f # TAILCALL
%b = lshr i32 %a, 2
%c = zext i32 %b to i64
%d = add i64 %c, 1
%e = shl i64 %c, 2
tail call void @f(i64 %e)
ret void
}
declare void @f(i64)