[InstCombine] Minor optimization for bswap with binary ops

Added instcombine optimizations for BSWAP with AND/OR/XOR ops:

OP( BSWAP(x), BSWAP(y) ) -> BSWAP( OP(x, y) )
OP( BSWAP(x), CONSTANT ) -> BSWAP( OP(x, BSWAP(CONSTANT) ) )

Since its just a one liner, I've also added BSWAP to the DAGCombiner equivalent as well:

fold (OP (bswap x), (bswap y)) -> (bswap (OP x, y))

Refactored bswap-fold tests to use FileCheck instead of just checking that the bswaps had gone.

Differential Revision: http://reviews.llvm.org/D6407

llvm-svn: 223349

1 files changed, 169 insertions, 15 deletions

diff --git a/llvm/test/Transforms/InstCombine/bswap-fold.ll b/llvm/test/Transforms/InstCombine/bswap-fold.ll
index 442ce58421e..63b0775e4af 100644
--- a/llvm/test/Transforms/InstCombine/bswap-fold.ll
+++ b/llvm/test/Transforms/InstCombine/bswap-fold.ll
@@ -1,63 +1,79 @@
-; RUN: opt < %s -instcombine -S | not grep call.*bswap
+; RUN: opt < %s -instcombine -S | FileCheck %s
 
 define i1 @test1(i16 %tmp2) {
+; CHECK-LABEL: @test1
+; CHECK-NEXT:  %tmp = icmp eq i16 %tmp2, 256
+; CHECK-NEXT:  ret i1 %tmp
         %tmp10 = call i16 @llvm.bswap.i16( i16 %tmp2 )
         %tmp = icmp eq i16 %tmp10, 1
         ret i1 %tmp
 }
 
 define i1 @test2(i32 %tmp) {
+; CHECK-LABEL: @test2
+; CHECK-NEXT:  %tmp.upgrd.1 = icmp eq i32 %tmp, 16777216
+; CHECK-NEXT:  ret i1 %tmp.upgrd.1
         %tmp34 = tail call i32 @llvm.bswap.i32( i32 %tmp )
         %tmp.upgrd.1 = icmp eq i32 %tmp34, 1
         ret i1 %tmp.upgrd.1
 }
 
-declare i32 @llvm.bswap.i32(i32)
-
 define i1 @test3(i64 %tmp) {
+; CHECK-LABEL: @test3
+; CHECK-NEXT:  %tmp.upgrd.2 = icmp eq i64 %tmp, 72057594037927936
+; CHECK-NEXT:  ret i1 %tmp.upgrd.2
         %tmp34 = tail call i64 @llvm.bswap.i64( i64 %tmp )
         %tmp.upgrd.2 = icmp eq i64 %tmp34, 1
         ret i1 %tmp.upgrd.2
 }
 
-declare i64 @llvm.bswap.i64(i64)
-
-declare i16 @llvm.bswap.i16(i16)
-
 ; rdar://5992453
 ; A & 255
 define i32 @test4(i32 %a) nounwind  {
-entry:
-	%tmp2 = tail call i32 @llvm.bswap.i32( i32 %a )	
+; CHECK-LABEL: @test4
+; CHECK-NEXT:  %tmp2 = and i32 %a, 255
+; CHECK-NEXT:  ret i32 %tmp2
+	%tmp2 = tail call i32 @llvm.bswap.i32( i32 %a )
 	%tmp4 = lshr i32 %tmp2, 24
 	ret i32 %tmp4
 }
 
 ; A
-define i32 @test5(i32 %a) nounwind  {
-entry:
+define i32 @test5(i32 %a) nounwind {
+; CHECK-LABEL: @test5
+; CHECK-NEXT:  ret i32 %a
 	%tmp2 = tail call i32 @llvm.bswap.i32( i32 %a )
 	%tmp4 = tail call i32 @llvm.bswap.i32( i32 %tmp2 )
 	ret i32 %tmp4
 }
 
 ; a >> 24
-define i32 @test6(i32 %a) nounwind  {
-entry:
-	%tmp2 = tail call i32 @llvm.bswap.i32( i32 %a )	
+define i32 @test6(i32 %a) nounwind {
+; CHECK-LABEL: @test6
+; CHECK-NEXT:  %tmp2 = lshr i32 %a, 24
+; CHECK-NEXT   ret i32 %tmp4
+	%tmp2 = tail call i32 @llvm.bswap.i32( i32 %a )
 	%tmp4 = and i32 %tmp2, 255
 	ret i32 %tmp4
 }
 
 ; PR5284
 define i16 @test7(i32 %A) {
-  %B = tail call i32 @llvm.bswap.i32(i32 %A) nounwind 
+; CHECK-LABEL: @test7
+; CHECK-NEXT:  %1 = lshr i32 %A, 16
+; CHECK-NEXT:  %D = trunc i32 %1 to i16
+; CHECK-NEXT   ret i16 %D
+  %B = tail call i32 @llvm.bswap.i32(i32 %A) nounwind
   %C = trunc i32 %B to i16
   %D = tail call i16 @llvm.bswap.i16(i16 %C) nounwind
   ret i16 %D
 }
 
 define i16 @test8(i64 %A) {
+; CHECK-LABEL: @test8
+; CHECK-NEXT:  %1 = lshr i64 %A, 48
+; CHECK-NEXT:  %D = trunc i64 %1 to i16
+; CHECK-NEXT   ret i16 %D
   %B = tail call i64 @llvm.bswap.i64(i64 %A) nounwind 
   %C = trunc i64 %B to i16
   %D = tail call i16 @llvm.bswap.i16(i16 %C) nounwind
@@ -66,6 +82,144 @@ define i16 @test8(i64 %A) {
 
 ; Misc: Fold bswap(undef) to undef.
 define i64 @foo() {
+; CHECK-LABEL: @foo
+; CHECK-NEXT: ret i64 undef
   %a = call i64 @llvm.bswap.i64(i64 undef)
   ret i64 %a
 }
+
+; PR15782
+; Fold: OP( BSWAP(x), BSWAP(y) ) -> BSWAP( OP(x, y) )
+; Fold: OP( BSWAP(x), CONSTANT ) -> BSWAP( OP(x, BSWAP(CONSTANT) ) )
+define i16 @bs_and16i(i16 %a, i16 %b) #0 {
+; CHECK-LABEL: @bs_and16i
+; CHECK-NEXT:  %1 = and i16 %a, 4391
+; CHECK-NEXT:  %2 = call i16 @llvm.bswap.i16(i16 %1)
+; CHECK-NEXT:  ret i16 %2
+  %1 = tail call i16 @llvm.bswap.i16(i16 %a)
+  %2 = and i16 %1, 10001
+  ret i16 %2
+}
+
+define i16 @bs_and16(i16 %a, i16 %b) #0 {
+; CHECK-LABEL: @bs_and16
+; CHECK-NEXT:  %1 = and i16 %a, %b
+; CHECK-NEXT:  %2 = call i16 @llvm.bswap.i16(i16 %1)
+; CHECK-NEXT:  ret i16 %2
+  %tmp1 = tail call i16 @llvm.bswap.i16(i16 %a)
+  %tmp2 = tail call i16 @llvm.bswap.i16(i16 %b)
+  %tmp3 = and i16 %tmp1, %tmp2
+  ret i16 %tmp3
+}
+
+define i16 @bs_or16(i16 %a, i16 %b) #0 {
+; CHECK-LABEL: @bs_or16
+; CHECK-NEXT:  %1 = or i16 %a, %b
+; CHECK-NEXT:  %2 = call i16 @llvm.bswap.i16(i16 %1)
+; CHECK-NEXT:  ret i16 %2
+  %tmp1 = tail call i16 @llvm.bswap.i16(i16 %a)
+  %tmp2 = tail call i16 @llvm.bswap.i16(i16 %b)
+  %tmp3 = or i16 %tmp1, %tmp2
+  ret i16 %tmp3
+}
+
+define i16 @bs_xor16(i16 %a, i16 %b) #0 {
+; CHECK-LABEL: @bs_xor16
+; CHECK-NEXT:  %1 = xor i16 %a, %b
+; CHECK-NEXT:  %2 = call i16 @llvm.bswap.i16(i16 %1)
+; CHECK-NEXT:  ret i16 %2
+  %tmp1 = tail call i16 @llvm.bswap.i16(i16 %a)
+  %tmp2 = tail call i16 @llvm.bswap.i16(i16 %b)
+  %tmp3 = xor i16 %tmp1, %tmp2
+  ret i16 %tmp3
+}
+
+define i32 @bs_and32i(i32 %a, i32 %b) #0 {
+; CHECK-LABEL: @bs_and32i
+; CHECK-NEXT:  %1 = and i32 %a, -1585053440
+; CHECK-NEXT:  %2 = call i32 @llvm.bswap.i32(i32 %1)
+; CHECK-NEXT:  ret i32 %2
+  %tmp1 = tail call i32 @llvm.bswap.i32(i32 %a)
+  %tmp2 = and i32 %tmp1, 100001
+  ret i32 %tmp2
+}
+
+define i32 @bs_and32(i32 %a, i32 %b) #0 {
+; CHECK-LABEL: @bs_and32
+; CHECK-NEXT:  %1 = and i32 %a, %b
+; CHECK-NEXT:  %2 = call i32 @llvm.bswap.i32(i32 %1)
+; CHECK-NEXT:  ret i32 %2
+  %tmp1 = tail call i32 @llvm.bswap.i32(i32 %a)
+  %tmp2 = tail call i32 @llvm.bswap.i32(i32 %b)
+  %tmp3 = and i32 %tmp1, %tmp2
+  ret i32 %tmp3
+}
+
+define i32 @bs_or32(i32 %a, i32 %b) #0 {
+; CHECK-LABEL: @bs_or32
+; CHECK-NEXT:  %1 = or i32 %a, %b
+; CHECK-NEXT:  %2 = call i32 @llvm.bswap.i32(i32 %1)
+; CHECK-NEXT:  ret i32 %2
+  %tmp1 = tail call i32 @llvm.bswap.i32(i32 %a)
+  %tmp2 = tail call i32 @llvm.bswap.i32(i32 %b)
+  %tmp3 = or i32 %tmp1, %tmp2
+  ret i32 %tmp3
+}
+
+define i32 @bs_xor32(i32 %a, i32 %b) #0 {
+; CHECK-LABEL: @bs_xor32
+; CHECK-NEXT:  %1 = xor i32 %a, %b
+; CHECK-NEXT:  %2 = call i32 @llvm.bswap.i32(i32 %1)
+; CHECK-NEXT:  ret i32 %2
+  %tmp1 = tail call i32 @llvm.bswap.i32(i32 %a)
+  %tmp2 = tail call i32 @llvm.bswap.i32(i32 %b)
+  %tmp3 = xor i32 %tmp1, %tmp2
+  ret i32 %tmp3
+}
+
+define i64 @bs_and64i(i64 %a, i64 %b) #0 {
+; CHECK-LABEL: @bs_and64i
+; CHECK-NEXT:  %1 = and i64 %a, 129085117527228416
+; CHECK-NEXT:  %2 = call i64 @llvm.bswap.i64(i64 %1)
+; CHECK-NEXT:  ret i64 %2
+  %tmp1 = tail call i64 @llvm.bswap.i64(i64 %a)
+  %tmp2 = and i64 %tmp1, 1000000001
+  ret i64 %tmp2
+}
+
+define i64 @bs_and64(i64 %a, i64 %b) #0 {
+; CHECK-LABEL: @bs_and64
+; CHECK-NEXT:  %1 = and i64 %a, %b
+; CHECK-NEXT:  %2 = call i64 @llvm.bswap.i64(i64 %1)
+; CHECK-NEXT:  ret i64 %2
+  %tmp1 = tail call i64 @llvm.bswap.i64(i64 %a)
+  %tmp2 = tail call i64 @llvm.bswap.i64(i64 %b)
+  %tmp3 = and i64 %tmp1, %tmp2
+  ret i64 %tmp3
+}
+
+define i64 @bs_or64(i64 %a, i64 %b) #0 {
+; CHECK-LABEL: @bs_or64
+; CHECK-NEXT:  %1 = or i64 %a, %b
+; CHECK-NEXT:  %2 = call i64 @llvm.bswap.i64(i64 %1)
+; CHECK-NEXT:  ret i64 %2
+  %tmp1 = tail call i64 @llvm.bswap.i64(i64 %a)
+  %tmp2 = tail call i64 @llvm.bswap.i64(i64 %b)
+  %tmp3 = or i64 %tmp1, %tmp2
+  ret i64 %tmp3
+}
+
+define i64 @bs_xor64(i64 %a, i64 %b) #0 {
+; CHECK-LABEL: @bs_xor64
+; CHECK-NEXT:  %1 = xor i64 %a, %b
+; CHECK-NEXT:  %2 = call i64 @llvm.bswap.i64(i64 %1)
+; CHECK-NEXT:  ret i64 %2
+  %tmp1 = tail call i64 @llvm.bswap.i64(i64 %a)
+  %tmp2 = tail call i64 @llvm.bswap.i64(i64 %b)
+  %tmp3 = xor i64 %tmp1, %tmp2
+  ret i64 %tmp3
+}
+
+declare i16 @llvm.bswap.i16(i16)
+declare i32 @llvm.bswap.i32(i32)
+declare i64 @llvm.bswap.i64(i64)