[ARM,AArch64] NFC. Add extra test cases for bswap lowering.

[• chatur01]

Summary

I mistakenly made this test cases as part of another review, may
as well offer them up instead of letting it go to waste.

[rengolin]

Missed this one... :)

[rengolin]

r269425

test/CodeGen/AArch64/bswap.ll

+; RUN: llc -march=aarch64 < %s | FileCheck %s
+
+; Test byte swap instrinsic lowering on AArch64 targets.
+
+define i16 @bswap16(i16 %x) #0 {
+  %1 = tail call i16 @llvm.bswap.i16(i16 %x)
+  ret i16 %1
+; CHECK-LABEL: bswap16
+; CHECK:       rev [[R0:w[0-9]+]], {{w[0-9]+}}
+; CHECK-NEXT:  lsr {{w[0-9]+}}, [[R0]], #16
+}
+
+define i32 @bswap32(i32 %x) #0 {
+  %1 = tail call i32 @llvm.bswap.i32(i32 %x)
+  ret i32 %1
+; CHECK-LABEL: bswap32
+; CHECK:       rev [[R0:w[0-9]+]], [[R0]]
+}
+
+define i48 @bswap48(i48 %x) #0 {
+  %1 = tail call i48 @llvm.bswap.i48(i48 %x)
+  ret i48 %1
+; CHECK-LABEL: bswap48
+; CHECK:       rev [[R0:x[0-9]+]], {{x[0-9]+}}
+; CHECK-NEXT:  lsr {{x[0-9]+}}, [[R0]], #16
+}
+
+define i64 @bswap64(i64 %x) #0 {
+  %1 = tail call i64 @llvm.bswap.i64(i64 %x)
+  ret i64 %1
+; CHECK-LABEL: bswap64
+; CHECK:       rev [[R0:x[0-9]+]], [[R0]]
+; CHECK-NOT:   rev
+}
+
+declare i16 @llvm.bswap.i16(i16)
+declare i32 @llvm.bswap.i32(i32)
+declare i48 @llvm.bswap.i48(i48)
+declare i64 @llvm.bswap.i64(i64)

test/CodeGen/ARM/bswap.ll

+; RUN: llc -march=arm -mattr=+v4t < %s | FileCheck -check-prefix PRE6 %s
+; RUN: llc -march=armeb -mattr=+v4t < %s | FileCheck -check-prefix PRE6BE %s
+; RUN: llc -march=arm -mattr=+v5t < %s | FileCheck -check-prefix PRE6 %s
+; RUN: llc -march=arm -mattr=+v5te < %s | FileCheck -check-prefix PRE6 %s
+; RUN: llc -march=arm -mattr=+v6 < %s | FileCheck -check-prefix REV %s
+; RUN: llc -march=armeb -mattr=+v6 < %s | FileCheck -check-prefix REVBE %s
+; RUN: llc -march=arm -mattr=+v6k < %s | FileCheck -check-prefix REV %s
+; RUN: llc -march=arm -mattr=+v6m < %s | FileCheck -check-prefix REV %s
+; RUN: llc -march=arm -mattr=+v6t2 < %s | FileCheck -check-prefix REV %s
+; RUN: llc -march=arm -mattr=+v7 < %s | FileCheck -check-prefix REV %s
+; RUN: llc -march=arm -mattr=+v8 < %s | FileCheck -check-prefix REV %s
+; RUN: llc -march=arm -mattr=+v8.1a < %s | FileCheck -check-prefix REV %s
+
+;; Test byte swap instrinsic lowering on ARM targets.
+
+;; The REV instruction only appeared in ARMv6 and later. Earlier
+;; supported architecture have to open-code this intrinsic.
+
+define i16 @bswap16(i16 %x) #0 {
+  %1 = tail call i16 @llvm.bswap.i16(i16 %x)
+  ret i16 %1
+; PRE6-LABEL: bswap16
+;; The source register patterns are all capable of matching a new
+;; register to avoid specifying allocation choices unnecessarily.
+; PRE6:       mov [[R1:r[0-9]+|lr]], #16711680
+; PRE6-NEXT:  and [[R2:r[0-9]+|lr]], [[R1]], [[R0:r[0-9]]], lsl #8
+; PRE6-NEXT:  orr [[R3:r[0-9]+|lr]], [[R2]], [[R0]], lsl #24
+; PRE6-NEXT:  lsr [[R4:r[0-9]+|lr]], [[R3]], #16
+
+; REV-LABEL: bswap16
+;; FIXME: It would ben nice if DAG legalization was taught to not
+;; promote the incoming reg to i32 in this case, so that the
+;; combiner could canonicalize this to (rotr (bswap x), 16), which
+;; would then get matched as REV16.
+; REV:      rev [[R0:r[0-9]+|lr]], {{r[0-9]+}}
+; REV-NEXT: lsr {{r[0-9]+}}, [[R0]], #16
+}
+
+define i32 @bswap32(i32 %x) #0 {
+  %1 = tail call i32 @llvm.bswap.i32(i32 %x)
+  ret i32 %1
+; PRE6-LABEL: bswap32
+; PRE6-DAG:   mov [[R0:r[0-9]+|lr]], #65280
+; PRE6-NOT:   DAG-BREAK!
+; PRE6-DAG:   and [[R0]], [[R0]], [[R1:r[0-9]+|lr]], lsr #8
+; PRE6-DAG:   orr [[R0]], [[R0]], [[R1]], lsr #24
+; PRE6-DAG:   mov [[R2:r[0-9]+|lr]], #16711680
+; PRE6-DAG:   and [[R2]], [[R2]], [[R1]], lsl #8
+; PRE6-DAG:   orr [[R1]], [[R2]], [[R1]], lsl #24
+; PRE6-NOT:   DAG-BREAK!
+; PRE6-DAG:   orr [[R1]], [[R1]], [[R0]]
+
+; REV-LABEL: bswap32
+; REV:       rev {{r[0-9]+|lr}}, {{r[0-9]+|lr}}
+; REV-NOT:   rev
+}
+
+define i48 @bswap48(i48 %x) #0 {
+  %1 = tail call i48 @llvm.bswap.i48(i48 %x)
+  ret i48 %1
+; PRE6-LABEL: bswap48
+; PRE6-DAG:   mov [[R0:r[0-9]+|lr]], #65280
+; PRE6-DAG:   mov [[R1:r[0-9]+|lr]], #16711680
+; PRE6-NOT:   DAG-BREAK!
+; PRE6-DAG:   and [[R0]], [[R0]], [[R2:r[0-9]+|lr]], lsr #8
+; PRE6-DAG:   and [[R3:r[0-9]+|lr]], [[R1]], [[R2]], lsl #8
+; PRE6-DAG:   orr [[R0]], [[R0]], [[R2]], lsr #24
+; PRE6-DAG:   orr [[R2]], [[R3]], [[R2]], lsl #24
+; PRE6-DAG:   orr [[R0]], [[R2]], [[R0]]
+; PRE6-NOT:   DAG-BREAK!
+; PRE6-DAG:   and [[R2]], [[R1]], [[R4:r[0-9]+|lr]], lsl #8
+; PRE6-DAG:   orr [[R2]], [[R2]], [[R4]], lsl #24
+; PRE6-DAG:   lsr [[R4]], [[R0]], #16
+; PRE6-DAG:   lsr [[R2]], [[R2]], #16
+; PRE6-NOT:   DAG-BREAK!
+; PRE6-DAG:   orr [[R2]], [[R2]], [[R0]], lsl #16
+
+; PRE6BE-LABEL: bswap48
+; PRE6BE-DAG: mov [[R0:r[0-9]+|lr]], #65280
+; PRE6BE-DAG: mov [[R1:r[0-9]+|lr]], #16711680
+; PRE6-NOT:   DAG-BREAK!
+; PRE6BE-DAG: and [[R0]], [[R0]], [[R2:r[0-9]+|lr]], lsr #8
+; PRE6BE-DAG: and [[R3:r[0-9]+|lr]], [[R1]], [[R2:r[0-9]+|lr]], lsl #8
+; PRE6BE-DAG: orr [[R0]], [[R0]], [[R2]], lsr #24
+; PRE6BE-DAG: orr [[R2]], [[R3]], [[R2]], lsl #24
+; PRE6BE-DAG: orr [[R0]], [[R2]], [[R0]]
+; PRE6-NOT:   DAG-BREAK!
+; PRE6BE-DAG: and [[R2]], [[R1]], [[R4:r[0-9]+|lr]], lsl #8
+; PRE6BE-DAG: orr [[R4]], [[R2]], [[R4]], lsl #24
+; PRE6BE-DAG: lsr [[R4]], [[R4]], #16
+; PRE6BE-DAG: lsr [[R4]], [[R0]], #16
+; PRE6-NOT:   DAG-BREAK!
+; PRE6BE-DAG: orr [[R2]], [[R4]], [[R0]], lsl #16
+
+; REV-LABEL: bswap48
+; REV-DAG:   rev [[R0:r[0-9]+]], [[R1:r[0-9]+]]
+; REV-DAG:   rev [[R1]], [[R2:r[0-9]+]]
+; REV-DAG:   lsr [[R1]], [[R1]], #16
+; REV-DAG:   lsr [[R2]], [[R0]], #16
+; REV-DAG:   orr [[R1]], [[R1]], [[R0]], lsl #16
+
+; REVBE-LABEL: bswap48
+; Until PR24879 is fixed, I can't match [[R0:r[0-9]+|lr]] in a
+; backreference. Having to stick to just r[0-9]+ for now, which
+; is *very* likely to be the register selection :-).
+; REVBE-DAG: rev [[R0:r[0-9]+]], [[R0]]
+; Need to break DAG block here to stop R1 or R2 clobbering the
+; self rev above.
+; REVBE-NEXT: rev [[R1:r[0-9]+|lr]], [[R2:r[0-9]+|lr]]
+; REVBE-DAG: lsr [[R0]], [[R0]], #16
+; REVBE-DAG: lsr [[R0]], [[R1]], #16
+; REVBE-DAG: orr [[R2]], [[R0]], [[R1]], lsl #16
+}
+
+define i64 @bswap64(i64 %x) #0 {
+  %1 = tail call i64 @llvm.bswap.i64(i64 %x)
+  ret i64 %1
+; PRE6-LABEL: bswap64
+; PRE6-DAG: mov [[R0:r[0-9]+|lr]], #65280
+; PRE6-DAG: mov [[R1:r[0-9]+|lr]], #16711680
+; PRE6-NOT:   DAG-BREAK!
+; PRE6-DAG: and [[R2:r[0-9]+|lr]], [[R0]], [[R3:r[0-9]+|lr]], lsr #8
+; PRE6-DAG: and [[R4:r[0-9]+|lr]], [[R1]], [[R3]], lsl #8
+; PRE6-DAG: orr [[R2]], [[R2]], [[R3]], lsr #24
+; PRE6:     orr [[R3]], [[R4]], [[R3]], lsl #24
+; PRE6-NOT: DAG-BREAK!
+; PRE6-DAG: and [[R4]], [[R1]], [[R5:r[0-9]+|lr]], lsl #8
+; PRE6-DAG: orr [[R2]], [[R3]], [[R2]]
+; PRE6-DAG: and [[R3]], [[R0]], [[R5]], lsr #8
+; PRE6-DAG: orr [[R3]], [[R3]], [[R5]], lsr #24
+; PRE6-DAG: orr [[R5]], [[R4]], [[R5]], lsl #24
+; PRE6-DAG: orr [[R3]], [[R5]], [[R3]]
+
+; REV-LABEL: bswap64
+; Just check that the two 32-bit words are reversed, not bothered
+; so much about regiter selection here.
+; REV:     rev
+; REV:     rev
+; REV-NOT: rev
+}
+
+declare i16 @llvm.bswap.i16(i16)
+declare i32 @llvm.bswap.i32(i32)
+declare i48 @llvm.bswap.i48(i48)
+declare i64 @llvm.bswap.i64(i64)