[PATCH] D150422: [ConstantFolding] fold integers whose bitwidth is greater than 63, and not multiplies of 8

[Kohei Asano via Phabricator via llvm-commits]

khei4 created this revision.
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This patch tries to fold integers whose bit width is greater than 63, and not multiplies of 8.

TODO: confirm the correctness of not multiplies of 8 integer.


https://reviews.llvm.org/D150422

Files:
  llvm/lib/Analysis/ConstantFolding.cpp
  llvm/test/CodeGen/X86/load-local-v4i5.ll
  llvm/test/Transforms/InstCombine/load-store-forward.ll


Index: llvm/test/Transforms/InstCombine/load-store-forward.ll
===================================================================
--- llvm/test/Transforms/InstCombine/load-store-forward.ll
+++ llvm/test/Transforms/InstCombine/load-store-forward.ll
@@ -39,10 +39,13 @@
 }
 
 define i17 @vec_store_load_first_odd_size(ptr %p) {
-; CHECK-LABEL: @vec_store_load_first_odd_size(
-; CHECK-NEXT:    store <2 x i17> <i17 1, i17 2>, ptr [[P:%.*]], align 8
-; CHECK-NEXT:    [[LOAD:%.*]] = load i17, ptr [[P]], align 4
-; CHECK-NEXT:    ret i17 [[LOAD]]
+; LITTLE-LABEL: @vec_store_load_first_odd_size(
+; LITTLE-NEXT:    store <2 x i17> <i17 1, i17 2>, ptr [[P:%.*]], align 8
+; LITTLE-NEXT:    ret i17 1
+;
+; BIG-LABEL: @vec_store_load_first_odd_size(
+; BIG-NEXT:    store <2 x i17> <i17 1, i17 2>, ptr [[P:%.*]], align 8
+; BIG-NEXT:    ret i17 256
 ;
   store <2 x i17> <i17 1, i17 2>, ptr %p
   %load = load i17, ptr %p
Index: llvm/test/CodeGen/X86/load-local-v4i5.ll
===================================================================
--- llvm/test/CodeGen/X86/load-local-v4i5.ll
+++ llvm/test/CodeGen/X86/load-local-v4i5.ll
@@ -6,27 +6,24 @@
 define void @_start() {
 ; CHECK-LABEL: _start:
 ; CHECK:       # %bb.0: # %Entry
-; CHECK-NEXT:    movl __unnamed_1(%rip), %eax
-; CHECK-NEXT:    movl %eax, -12(%rsp)
-; CHECK-NEXT:    movzbl -9(%rsp), %ecx
+; CHECK-NEXT:    movl $0, -12(%rsp)
+; CHECK-NEXT:    movzbl -9(%rsp), %eax
+; CHECK-NEXT:    movzbl -11(%rsp), %ecx
 ; CHECK-NEXT:    movzbl -10(%rsp), %edx
-; CHECK-NEXT:    movzbl -11(%rsp), %esi
-; CHECK-NEXT:    movzbl %cl, %edi
-; CHECK-NEXT:    shrb %cl
-; CHECK-NEXT:    movb %cl, -2(%rsp)
-; CHECK-NEXT:    andl $31, %eax
-; CHECK-NEXT:    andl $31, %esi
-; CHECK-NEXT:    shll $5, %esi
-; CHECK-NEXT:    orl %eax, %esi
+; CHECK-NEXT:    movzbl %al, %esi
+; CHECK-NEXT:    shrb %al
+; CHECK-NEXT:    movb %al, -2(%rsp)
 ; CHECK-NEXT:    andl $31, %edx
 ; CHECK-NEXT:    shll $10, %edx
-; CHECK-NEXT:    orl %esi, %edx
-; CHECK-NEXT:    movl %edi, %eax
+; CHECK-NEXT:    andl $31, %ecx
+; CHECK-NEXT:    shll $5, %ecx
+; CHECK-NEXT:    orl %edx, %ecx
+; CHECK-NEXT:    movl %esi, %eax
 ; CHECK-NEXT:    shll $15, %eax
-; CHECK-NEXT:    orl %edx, %eax
+; CHECK-NEXT:    orl %ecx, %eax
 ; CHECK-NEXT:    movw %ax, -4(%rsp)
-; CHECK-NEXT:    movb %dil, -5(%rsp)
-; CHECK-NEXT:    cmpb $31, %dil
+; CHECK-NEXT:    movb %sil, -5(%rsp)
+; CHECK-NEXT:    cmpb $31, %sil
 ; CHECK-NEXT:    je .LBB0_2
 ; CHECK-NEXT:  # %bb.1: # %Then
 ; CHECK-NEXT:    int3
Index: llvm/lib/Analysis/ConstantFolding.cpp
===================================================================
--- llvm/lib/Analysis/ConstantFolding.cpp
+++ llvm/lib/Analysis/ConstantFolding.cpp
@@ -429,10 +429,6 @@
     return true;
 
   if (auto *CI = dyn_cast<ConstantInt>(C)) {
-    if (CI->getBitWidth() > 64 ||
-        (CI->getBitWidth() & 7) != 0)
-      return false;
-
     uint64_t Val = CI->getZExtValue();
     unsigned IntBytes = unsigned(CI->getBitWidth()/8);
 


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