[Reassociate] Add initial support for vector instructions.

This patch adds initial support for vector instructions to the reassociation
pass. It enables most parts of the pass to work with vectors but to keep the
size of the patch small, optimization of Xor trees, canonicalization of
negative constants and converting shifts to muls, etc., have been left out.
This will be handled in later patches.

The patch is based on an initial patch by Chad Rosier.

Differential Revision: http://reviews.llvm.org/D7566

llvm-svn: 232190

1 files changed, 189 insertions, 43 deletions

diff --git a/llvm/test/Transforms/Reassociate/fast-ReassociateVector.ll b/llvm/test/Transforms/Reassociate/fast-ReassociateVector.ll
index eeae096bf94..9fbb5ccfe9a 100644
--- a/llvm/test/Transforms/Reassociate/fast-ReassociateVector.ll
+++ b/llvm/test/Transforms/Reassociate/fast-ReassociateVector.ll
@@ -1,46 +1,192 @@
 ; RUN: opt < %s -reassociate -S | FileCheck %s
 
-; Canonicalize operands, but don't optimize floating point vector operations.
-define <4 x float> @test1() {
-; CHECK-LABEL: test1
-; CHECK-NEXT: %tmp1 = fsub fast <4 x float> zeroinitializer, zeroinitializer
-; CHECK-NEXT: %tmp2 = fmul fast <4 x float> %tmp1, zeroinitializer
-
-  %tmp1 = fsub fast <4 x float> zeroinitializer, zeroinitializer
-  %tmp2 = fmul fast <4 x float> zeroinitializer, %tmp1
-  ret <4 x float> %tmp2
-}
-
-; Commute integer vector operations.
-define <2 x i32> @test2(<2 x i32> %x, <2 x i32> %y) {
-; CHECK-LABEL: test2
-; CHECK-NEXT: %tmp1 = add <2 x i32> %x, %y
-; CHECK-NEXT: %tmp2 = add <2 x i32> %x, %y
-; CHECK-NEXT: %tmp3 = add <2 x i32> %tmp1, %tmp2
-
-  %tmp1 = add <2 x i32> %x, %y
-  %tmp2 = add <2 x i32> %y, %x
-  %tmp3 = add <2 x i32> %tmp1, %tmp2
-  ret <2 x i32> %tmp3
+; Check that a*c+b*c is turned into (a+b)*c
+define <4 x float> @test1(<4 x float> %a, <4 x float> %b, <4 x float> %c) {
+; CHECK-LABEL: @test1
+; CHECK-NEXT: %tmp = fadd fast <4 x float> %b, %a
+; CHECK-NEXT: %tmp1 = fmul fast <4 x float> %tmp, %c
+; CHECK-NEXT: ret <4 x float> %tmp1
+
+  %mul = fmul fast <4 x float> %a, %c
+  %mul1 = fmul fast <4 x float> %b, %c
+  %add = fadd fast <4 x float> %mul, %mul1
+  ret <4 x float> %add
 }
 
-define <2 x i32> @test3(<2 x i32> %x, <2 x i32> %y) {
-; CHECK-LABEL: test3
-; CHECK-NEXT: %tmp1 = mul <2 x i32> %x, %y
-; CHECK-NEXT: %tmp2 = mul <2 x i32> %x, %y
-; CHECK-NEXT: %tmp3 = mul <2 x i32> %tmp1, %tmp2
+; Check that a*a*b+a*a*c is turned into a*(a*(b+c)).
+define <2 x float> @test2(<2 x float> %a, <2 x float> %b, <2 x float> %c) {
+; CHECK-LABEL: @test2
+; CHECK-NEXT: fadd fast <2 x float> %c, %b
+; CHECK-NEXT: fmul fast <2 x float> %a, %tmp2
+; CHECK-NEXT: fmul fast <2 x float> %tmp3, %a
+; CHECK-NEXT: ret <2 x float>
 
-  %tmp1 = mul <2 x i32> %x, %y
-  %tmp2 = mul <2 x i32> %y, %x
-  %tmp3 = mul <2 x i32> %tmp1, %tmp2
-  ret <2 x i32> %tmp3
+  %t0 = fmul fast <2 x float> %a, %b
+  %t1 = fmul fast <2 x float> %a, %t0
+  %t2 = fmul fast <2 x float> %a, %c
+  %t3 = fmul fast <2 x float> %a, %t2
+  %t4 = fadd fast <2 x float> %t1, %t3
+  ret <2 x float> %t4
+}
+
+; Check that a*b+a*c+d is turned into a*(b+c)+d.
+define <2 x double> @test3(<2 x double> %a, <2 x double> %b, <2 x double> %c, <2 x double> %d) {
+; CHECK-LABEL: @test3
+; CHECK-NEXT: fadd fast <2 x double> %c, %b
+; CHECK-NEXT: fmul fast <2 x double> %tmp, %a
+; CHECK-NEXT: fadd fast <2 x double> %tmp1, %d
+; CHECK-NEXT: ret <2 x double>
+
+  %t0 = fmul fast <2 x double> %a, %b
+  %t1 = fmul fast <2 x double> %a, %c
+  %t2 = fadd fast <2 x double> %t1, %d
+  %t3 = fadd fast <2 x double> %t0, %t2
+  ret <2 x double> %t3
+}
+
+; No fast-math.
+define <2 x float> @test4(<2 x float> %A) {
+; CHECK-LABEL: @test4
+; CHECK-NEXT: %X = fadd <2 x float> %A, <float 1.000000e+00, float 1.000000e+00>
+; CHECK-NEXT: %Y = fadd <2 x float> %A, <float 1.000000e+00, float 1.000000e+00>
+; CHECK-NEXT: %R = fsub <2 x float> %X, %Y
+; CHECK-NEXT: ret <2 x float> %R
+
+  %X = fadd <2 x float> %A, < float 1.000000e+00, float 1.000000e+00 >
+  %Y = fadd <2 x float> %A, < float 1.000000e+00, float 1.000000e+00 >
+  %R = fsub <2 x float> %X, %Y
+  ret <2 x float> %R
+}
+
+; Check 47*X + 47*X -> 94*X.
+define <2 x float> @test5(<2 x float> %X) {
+; CHECK-LABEL: @test5
+; CHECK-NEXT: fmul fast <2 x float> %X, <float 9.400000e+01, float 9.400000e+01>
+; CHECK-NEXT: ret <2 x float>
+
+  %Y = fmul fast <2 x float> %X, <float 4.700000e+01, float 4.700000e+01>
+  %Z = fadd fast <2 x float> %Y, %Y
+  ret <2 x float> %Z
+}
+
+; Check X+X+X -> 3*X.
+define <2 x float> @test6(<2 x float> %X) {
+; CHECK-LABEL: @test6
+; CHECK-NEXT: fmul fast <2 x float> %X, <float 3.000000e+00, float 3.000000e+00>
+; CHECK-NEXT: ret <2 x float>
+
+  %Y = fadd fast <2 x float> %X ,%X
+  %Z = fadd fast <2 x float> %Y, %X
+  ret <2 x float> %Z
+}
+
+; Check 127*W+50*W -> 177*W.
+define <2 x double> @test7(<2 x double> %W) {
+; CHECK-LABEL: @test7
+; CHECK-NEXT: fmul fast <2 x double> %W, <double 1.770000e+02, double 1.770000e+02>
+; CHECK-NEXT: ret <2 x double>
+
+  %X = fmul fast <2 x double> %W, <double 127.0, double 127.0>
+  %Y = fmul fast <2 x double> %W, <double 50.0, double 50.0>
+  %Z = fadd fast <2 x double> %Y, %X
+  ret <2 x double> %Z
+}
+
+; Check X*12*12 -> X*144.
+define <2 x float> @test8(<2 x float> %arg) {
+; CHECK-LABEL: @test8
+; CHECK: fmul fast <2 x float> %arg, <float 1.440000e+02, float 1.440000e+02>
+; CHECK-NEXT: ret <2 x float> %tmp2
+
+  %tmp1 = fmul fast <2 x float> <float 1.200000e+01, float 1.200000e+01>, %arg
+  %tmp2 = fmul fast <2 x float> %tmp1, <float 1.200000e+01, float 1.200000e+01>
+  ret <2 x float> %tmp2
+}
+
+; Check (b+(a+1234))+-a -> b+1234.
+define <2 x double> @test9(<2 x double> %b, <2 x double> %a) {
+; CHECK-LABEL: @test9
+; CHECK: fadd fast <2 x double> %b, <double 1.234000e+03, double 1.234000e+03>
+; CHECK-NEXT: ret <2 x double>
+
+  %1 = fadd fast <2 x double> %a, <double 1.234000e+03, double 1.234000e+03>
+  %2 = fadd fast <2 x double> %b, %1
+  %3 = fsub fast <2 x double> <double 0.000000e+00, double 0.000000e+00>, %a
+  %4 = fadd fast <2 x double> %2, %3
+  ret <2 x double> %4
+}
+
+; Check -(-(z*40)*a) -> a*40*z.
+define <2 x float> @test10(<2 x float> %a, <2 x float> %b, <2 x float> %z) {
+; CHECK-LABEL: @test10
+; CHECK: fmul fast <2 x float> %a, <float 4.000000e+01, float 4.000000e+01>
+; CHECK-NEXT: fmul fast <2 x float> %e, %z
+; CHECK-NEXT: ret <2 x float>
+
+  %d = fmul fast <2 x float> %z, <float 4.000000e+01, float 4.000000e+01>
+  %c = fsub fast <2 x float> <float 0.000000e+00, float 0.000000e+00>, %d
+  %e = fmul fast <2 x float> %a, %c
+  %f = fsub fast <2 x float> <float 0.000000e+00, float 0.000000e+00>, %e
+  ret <2 x float> %f
+}
+
+; Check x*y+y*x -> x*y*2.
+define <2 x double> @test11(<2 x double> %x, <2 x double> %y) {
+; CHECK-LABEL: @test11
+; CHECK-NEXT: %factor = fmul fast <2 x double> %y, <double 2.000000e+00, double 2.000000e+00>
+; CHECK-NEXT: %tmp1 = fmul fast <2 x double> %factor, %x
+; CHECK-NEXT: ret <2 x double> %tmp1
+
+  %1 = fmul fast <2 x double> %x, %y
+  %2 = fmul fast <2 x double> %y, %x
+  %3 = fadd fast <2 x double> %1, %2
+  ret <2 x double> %3
+}
+
+; FIXME: shifts should be converted to mul to assist further reassociation.
+define <2 x i64> @test12(<2 x i64> %b, <2 x i64> %c) {
+; CHECK-LABEL: @test12
+; CHECK-NEXT:  %mul = mul <2 x i64> %c, %b
+; CHECK-NEXT:  %shl = shl <2 x i64> %mul, <i64 5, i64 5>
+; CHECK-NEXT:  ret <2 x i64> %shl
+
+  %mul = mul <2 x i64> %c, %b
+  %shl = shl <2 x i64> %mul, <i64 5, i64 5>
+  ret <2 x i64> %shl
+}
+
+; FIXME: expressions with a negative const should be canonicalized to assist
+; further reassociation.
+; We would expect (-5*b)+a -> a-(5*b) but only the constant operand is commuted.
+define <4 x float> @test13(<4 x float> %a, <4 x float> %b) {
+; CHECK-LABEL: @test13
+; CHECK-NEXT:  %mul = fmul fast <4 x float> %b, <float -5.000000e+00, float -5.000000e+00, float -5.000000e+00, float -5.000000e+00>
+; CHECK-NEXT:  %add = fadd fast <4 x float> %mul, %a
+; CHECK-NEXT:  ret <4 x float> %add
+
+  %mul = fmul fast <4 x float> <float -5.000000e+00, float -5.000000e+00, float -5.000000e+00, float -5.000000e+00>, %b
+  %add = fadd fast <4 x float> %mul, %a
+  ret <4 x float> %add
+}
+
+; Break up subtract to assist further reassociation.
+; Check a+b-c -> a+b+-c.
+define <2 x i64> @test14(<2 x i64> %a, <2 x i64> %b, <2 x i64> %c) {
+; CHECK-LABEL: @test14
+; CHECK-NEXT: %add = add <2 x i64> %b, %a
+; CHECK-NEXT: %c.neg = sub <2 x i64> zeroinitializer, %c
+; CHECK-NEXT: %sub = add <2 x i64> %add, %c.neg
+; CHECK-NEXT: ret <2 x i64> %sub
+
+  %add = add <2 x i64> %b, %a
+  %sub = sub <2 x i64> %add, %c
+  ret <2 x i64> %sub
 }
 
-define <2 x i32> @test4(<2 x i32> %x, <2 x i32> %y) {
-; CHECK-LABEL: test4
-; CHECK-NEXT: %tmp1 = and <2 x i32> %x, %y
-; CHECK-NEXT: %tmp2 = and <2 x i32> %x, %y
-; CHECK-NEXT: %tmp3 = and <2 x i32> %tmp1, %tmp2
+define <2 x i32> @test15(<2 x i32> %x, <2 x i32> %y) {
+; CHECK-LABEL: test15
+; CHECK-NEXT: %tmp3 = and <2 x i32> %y, %x
+; CHECK-NEXT: ret <2 x i32> %tmp3
 
   %tmp1 = and <2 x i32> %x, %y
   %tmp2 = and <2 x i32> %y, %x
@@ -48,11 +194,10 @@ define <2 x i32> @test4(<2 x i32> %x, <2 x i32> %y) {
   ret <2 x i32> %tmp3
 }
 
-define <2 x i32> @test5(<2 x i32> %x, <2 x i32> %y) {
-; CHECK-LABEL: test5
-; CHECK-NEXT: %tmp1 = or <2 x i32> %x, %y
-; CHECK-NEXT: %tmp2 = or <2 x i32> %x, %y
-; CHECK-NEXT: %tmp3 = or <2 x i32> %tmp1, %tmp2
+define <2 x i32> @test16(<2 x i32> %x, <2 x i32> %y) {
+; CHECK-LABEL: test16
+; CHECK-NEXT: %tmp3 = or <2 x i32> %y, %x
+; CHECK-NEXT: ret <2 x i32> %tmp3
 
   %tmp1 = or <2 x i32> %x, %y
   %tmp2 = or <2 x i32> %y, %x
@@ -60,8 +205,9 @@ define <2 x i32> @test5(<2 x i32> %x, <2 x i32> %y) {
   ret <2 x i32> %tmp3
 }
 
-define <2 x i32> @test6(<2 x i32> %x, <2 x i32> %y) {
-; CHECK-LABEL: test6
+; FIXME: Optimize vector xor.  Currently only commute operands.
+define <2 x i32> @test17(<2 x i32> %x, <2 x i32> %y) {
+; CHECK-LABEL: test17
 ; CHECK-NEXT: %tmp1 = xor <2 x i32> %x, %y
 ; CHECK-NEXT: %tmp2 = xor <2 x i32> %x, %y
 ; CHECK-NEXT: %tmp3 = xor <2 x i32> %tmp1, %tmp2