[llvm] r309535 - [X86] Add pattern to use bzhi for 64-bit 'and' with a mask when there is a load involved.

[Craig Topper via llvm-commits]

Author: ctopper
Date: Sun Jul 30 22:55:54 2017
New Revision: 309535

URL: http://llvm.org/viewvc/llvm-project?rev=309535&view=rev
Log:
[X86] Add pattern to use bzhi for 64-bit 'and' with a mask when there is a load involved.

We already had a pattern without load, but with a load we were falling back to a regular 'and' due to pattern complexity priority.

Modified:
    llvm/trunk/lib/Target/X86/X86InstrInfo.td
    llvm/trunk/test/CodeGen/X86/bmi.ll

Modified: llvm/trunk/lib/Target/X86/X86InstrInfo.td
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86InstrInfo.td?rev=309535&r1=309534&r2=309535&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86InstrInfo.td (original)
+++ llvm/trunk/lib/Target/X86/X86InstrInfo.td Sun Jul 30 22:55:54 2017
@@ -2361,6 +2361,10 @@ let Predicates = [HasBMI2] in {
             (BZHI64rr GR64:$src,
               (INSERT_SUBREG (i64 (IMPLICIT_DEF)),
                              (MOV8ri (CountTrailingOnes imm:$mask)), sub_8bit))>;
+  def : Pat<(and (loadi64 addr:$src), BZHIMask:$mask),
+            (BZHI64rm addr:$src,
+              (INSERT_SUBREG (i64 (IMPLICIT_DEF)),
+                             (MOV8ri (CountTrailingOnes imm:$mask)), sub_8bit))>;
 
   def : Pat<(and GR32:$src, (add (shl 1, GR8:$lz), -1)),
             (BZHI32rr GR32:$src,

Modified: llvm/trunk/test/CodeGen/X86/bmi.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/bmi.ll?rev=309535&r1=309534&r2=309535&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/bmi.ll (original)
+++ llvm/trunk/test/CodeGen/X86/bmi.ll Sun Jul 30 22:55:54 2017
@@ -555,6 +555,18 @@ entry:
   ret i64 %and
 }
 
+define i64 @bzhi64_constant_mask_load(i64* %x) {
+; CHECK-LABEL: bzhi64_constant_mask_load:
+; CHECK:       # BB#0: # %entry
+; CHECK-NEXT:    movb $62, %al
+; CHECK-NEXT:    bzhiq %rax, (%rdi), %rax
+; CHECK-NEXT:    retq
+entry:
+  %x1 = load i64, i64* %x
+  %and = and i64 %x1, 4611686018427387903
+  ret i64 %and
+}
+
 define i64 @bzhi64_small_constant_mask(i64 %x) {
 ; CHECK-LABEL: bzhi64_small_constant_mask:
 ; CHECK:       # BB#0: # %entry