[llvm-commits] [llvm] r78030 - in /llvm/trunk: lib/Target/ARM/ARMInstrThumb2.td test/CodeGen/Thumb2/thumb2-sub.ll

[Evan Cheng]

Author: evancheng
Date: Mon Aug  3 20:41:15 2009
New Revision: 78030

URL: http://llvm.org/viewvc/llvm-project?rev=78030&view=rev
Log:
Emit sub r, #c instead of transforming it to add r, #-c if c fits in 8-bit. This is a bit of pre-mature optimization. 8-bit variant makes it likely it will be narrowed to a 16-bit instruction.

Modified:
    llvm/trunk/lib/Target/ARM/ARMInstrThumb2.td
    llvm/trunk/test/CodeGen/Thumb2/thumb2-sub.ll

Modified: llvm/trunk/lib/Target/ARM/ARMInstrThumb2.td
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMInstrThumb2.td?rev=78030&r1=78029&r2=78030&view=diff

==============================================================================
--- llvm/trunk/lib/Target/ARM/ARMInstrThumb2.td (original)
+++ llvm/trunk/lib/Target/ARM/ARMInstrThumb2.td Mon Aug  3 20:41:15 2009
@@ -83,6 +83,10 @@
  return (uint32_t)(-N->getZExtValue()) < 4096; 
 }], imm_neg_XFORM>; 
 
+def imm0_255_neg : PatLeaf<(i32 imm), [{
+  return (uint32_t)(-N->getZExtValue()) < 255;
+}], imm_neg_XFORM>; 
+
 /// imm0_65535 predicate - True if the 32-bit immediate is in the range 
 /// [0.65535].
 def imm0_65535 : PatLeaf<(i32 imm), [{
@@ -619,12 +623,12 @@
 let mayLoad = 1 in
 def t2LDM : T2XI<(outs),
                  (ins addrmode4:$addr, pred:$p, reglist:$dst1, variable_ops),
-                 "ldm${addr:submode}${p}.w $addr, $dst1", []>;
+                 "ldm${addr:submode}${p} $addr, $dst1", []>;
 
 let mayStore = 1 in
 def t2STM : T2XI<(outs),
                  (ins addrmode4:$addr, pred:$p, reglist:$src1, variable_ops),
-                 "stm${addr:submode}${p}.w $addr, $src1", []>;
+                 "stm${addr:submode}${p} $addr, $src1", []>;
 
 //===----------------------------------------------------------------------===//
 //  Move Instructions.
@@ -704,6 +708,9 @@
 defm t2RSBS : T2I_rbin_s_is <"rsb", BinOpFrag<(subc node:$LHS, node:$RHS)>>;
 
 // (sub X, imm) gets canonicalized to (add X, -imm).  Match this form.
+let AddedComplexity = 1 in
+def : T2Pat<(add       GPR:$src, imm0_255_neg:$imm),
+            (t2SUBri   GPR:$src, imm0_255_neg:$imm)>;
 def : T2Pat<(add       GPR:$src, t2_so_imm_neg:$imm),
             (t2SUBri   GPR:$src, t2_so_imm_neg:$imm)>;
 def : T2Pat<(add       GPR:$src, imm0_4095_neg:$imm),

Modified: llvm/trunk/test/CodeGen/Thumb2/thumb2-sub.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/Thumb2/thumb2-sub.ll?rev=78030&r1=78029&r2=78030&view=diff

==============================================================================
--- llvm/trunk/test/CodeGen/Thumb2/thumb2-sub.ll (original)
+++ llvm/trunk/test/CodeGen/Thumb2/thumb2-sub.ll Mon Aug  3 20:41:15 2009
@@ -1,31 +1,49 @@
-; RUN: llvm-as < %s | llc -march=thumb -mattr=+thumb2 | grep {sub\\.w\\W*r\[0-9\],\\W*r\[0-9\],\\W*#\[0-9\]*} | grep {#171\\|#1179666\\|#872428544\\|#1448498774\\|#510} | count 5
+; RUN: llvm-as < %s | llc -march=thumb -mattr=+thumb2 | FileCheck %s
 
 ; 171 = 0x000000ab
 define i32 @f1(i32 %a) {
+; CHECK: f1:
+; CHECK: sub.w r0, r0, #171
     %tmp = sub i32 %a, 171
     ret i32 %tmp
 }
 
 ; 1179666 = 0x00120012
 define i32 @f2(i32 %a) {
+; CHECK: f2:
+; CHECK: sub.w r0, r0, #1179666
     %tmp = sub i32 %a, 1179666
     ret i32 %tmp
 }
 
 ; 872428544 = 0x34003400
 define i32 @f3(i32 %a) {
+; CHECK: f3:
+; CHECK: sub.w r0, r0, #872428544
     %tmp = sub i32 %a, 872428544
     ret i32 %tmp
 }
 
 ; 1448498774 = 0x56565656
 define i32 @f4(i32 %a) {
+; CHECK: f4:
+; CHECK: sub.w r0, r0, #1448498774
     %tmp = sub i32 %a, 1448498774
     ret i32 %tmp
 }
 
 ; 510 = 0x000001fe
 define i32 @f5(i32 %a) {
+; CHECK: f5:
+; CHECK: sub.w r0, r0, #510
     %tmp = sub i32 %a, 510
     ret i32 %tmp
 }
+
+; Don't change this to an add.
+define i32 @f6(i32 %a) {
+; CHECK: f6:
+; CHECK: sub.w r0, r0, #1
+    %tmp = sub i32 %a, 1
+    ret i32 %tmp
+}