[llvm] r252363 - [X86] Fold (trunc (i32 (zextload i16))) into vbroadcast.

[Ahmed Bougacha via llvm-commits]

Author: ab
Date: Fri Nov  6 17:16:48 2015
New Revision: 252363

URL: http://llvm.org/viewvc/llvm-project?rev=252363&view=rev
Log:
[X86] Fold (trunc (i32 (zextload i16))) into vbroadcast.

When matching non-LSB-extracting truncating broadcasts, we now insert
the necessary SRL. If the scalar resulted from a load, the SRL will be
folded into it, creating a narrower, offset, load.

However, i16 loads aren't Desirable, so we get i16->i32 zextloads.
We already catch i16 aextloads; catch these as well.

Modified:
    llvm/trunk/lib/Target/X86/X86InstrSSE.td
    llvm/trunk/test/CodeGen/X86/vector-shuffle-128-v8.ll
    llvm/trunk/test/CodeGen/X86/vector-shuffle-256-v16.ll

Modified: llvm/trunk/lib/Target/X86/X86InstrSSE.td
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86InstrSSE.td?rev=252363&r1=252362&r2=252363&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86InstrSSE.td (original)
+++ llvm/trunk/lib/Target/X86/X86InstrSSE.td Fri Nov  6 17:16:48 2015
@@ -8365,6 +8365,12 @@ let Predicates = [HasAVX2] in {
             (VPBROADCASTWrm addr:$src)>;
   def : Pat<(v16i16 (X86VBroadcast (i16 (trunc (i32 (load addr:$src)))))),
             (VPBROADCASTWYrm addr:$src)>;
+  def : Pat<(v8i16 (X86VBroadcast
+              (i16 (trunc (i32 (zextloadi16 addr:$src)))))),
+            (VPBROADCASTWrm addr:$src)>;
+  def : Pat<(v16i16 (X86VBroadcast
+              (i16 (trunc (i32 (zextloadi16 addr:$src)))))),
+            (VPBROADCASTWYrm addr:$src)>;
 
   // Provide aliases for broadcast from the same register class that
   // automatically does the extract.

Modified: llvm/trunk/test/CodeGen/X86/vector-shuffle-128-v8.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/vector-shuffle-128-v8.ll?rev=252363&r1=252362&r2=252363&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/vector-shuffle-128-v8.ll (original)
+++ llvm/trunk/test/CodeGen/X86/vector-shuffle-128-v8.ll Fri Nov  6 17:16:48 2015
@@ -2258,9 +2258,7 @@ define <8 x i16> @insert_dup_elt1_mem_v8
 ;
 ; AVX2-LABEL: insert_dup_elt1_mem_v8i16_i32:
 ; AVX2:       # BB#0:
-; AVX2-NEXT:    movzwl 2(%rdi), %eax
-; AVX2-NEXT:    vmovd %eax, %xmm0
-; AVX2-NEXT:    vpbroadcastw %xmm0, %xmm0
+; AVX2-NEXT:    vpbroadcastw 2(%rdi), %xmm0
 ; AVX2-NEXT:    retq
   %tmp = load i32, i32* %ptr, align 4
   %tmp1 = insertelement <4 x i32> zeroinitializer, i32 %tmp, i32 0
@@ -2298,9 +2296,7 @@ define <8 x i16> @insert_dup_elt3_mem_v8
 ;
 ; AVX2-LABEL: insert_dup_elt3_mem_v8i16_i32:
 ; AVX2:       # BB#0:
-; AVX2-NEXT:    movzwl 2(%rdi), %eax
-; AVX2-NEXT:    vmovd %eax, %xmm0
-; AVX2-NEXT:    vpbroadcastw %xmm0, %xmm0
+; AVX2-NEXT:    vpbroadcastw 2(%rdi), %xmm0
 ; AVX2-NEXT:    retq
   %tmp = load i32, i32* %ptr, align 4
   %tmp1 = insertelement <4 x i32> zeroinitializer, i32 %tmp, i32 1

Modified: llvm/trunk/test/CodeGen/X86/vector-shuffle-256-v16.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/vector-shuffle-256-v16.ll?rev=252363&r1=252362&r2=252363&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/vector-shuffle-256-v16.ll (original)
+++ llvm/trunk/test/CodeGen/X86/vector-shuffle-256-v16.ll Fri Nov  6 17:16:48 2015
@@ -3342,9 +3342,7 @@ define <16 x i16> @insert_dup_elt1_mem_v
 ;
 ; AVX2-LABEL: insert_dup_elt1_mem_v16i16_i32:
 ; AVX2:       # BB#0:
-; AVX2-NEXT:    movzwl 2(%rdi), %eax
-; AVX2-NEXT:    vmovd %eax, %xmm0
-; AVX2-NEXT:    vpbroadcastw %xmm0, %ymm0
+; AVX2-NEXT:    vpbroadcastw 2(%rdi), %ymm0
 ; AVX2-NEXT:    retq
   %tmp = load i32, i32* %ptr, align 4
   %tmp1 = insertelement <4 x i32> zeroinitializer, i32 %tmp, i32 0
@@ -3363,9 +3361,7 @@ define <16 x i16> @insert_dup_elt3_mem_v
 ;
 ; AVX2-LABEL: insert_dup_elt3_mem_v16i16_i32:
 ; AVX2:       # BB#0:
-; AVX2-NEXT:    movzwl 2(%rdi), %eax
-; AVX2-NEXT:    vmovd %eax, %xmm0
-; AVX2-NEXT:    vpbroadcastw %xmm0, %ymm0
+; AVX2-NEXT:    vpbroadcastw 2(%rdi), %ymm0
 ; AVX2-NEXT:    retq
   %tmp = load i32, i32* %ptr, align 4
   %tmp1 = insertelement <4 x i32> zeroinitializer, i32 %tmp, i32 1