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author | Chris Lattner <sabre@nondot.org> | 2008-02-19 17:37:35 +0000 |
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committer | Chris Lattner <sabre@nondot.org> | 2008-02-19 17:37:35 +0000 |
commit | ce2bcc8839834b5f5c5efbf269f547aafb638df4 (patch) | |
tree | 5240754ad82ae5cc04d154dd572ccac16f831f2e | |
parent | 22c31769fb1448dba3247780181d527a852d7694 (diff) | |
download | llvm-ce2bcc8839834b5f5c5efbf269f547aafb638df4.tar.gz llvm-ce2bcc8839834b5f5c5efbf269f547aafb638df4.tar.bz2 llvm-ce2bcc8839834b5f5c5efbf269f547aafb638df4.tar.xz |
Don't fold and's into test instructions if they have multiple uses.
This compiles test-nofold.ll into:
_test:
movl $15, %ecx
andl 4(%esp), %ecx
testl %ecx, %ecx
movl $42, %eax
cmove %ecx, %eax
ret
instead of:
_test:
movl 4(%esp), %eax
movl %eax, %ecx
andl $15, %ecx
testl $15, %eax
movl $42, %eax
cmove %ecx, %eax
ret
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47330 91177308-0d34-0410-b5e6-96231b3b80d8
-rw-r--r-- | lib/Target/X86/X86InstrInfo.td | 18 | ||||
-rw-r--r-- | test/CodeGen/X86/test-nofold.ll | 29 |
2 files changed, 41 insertions, 6 deletions
diff --git a/lib/Target/X86/X86InstrInfo.td b/lib/Target/X86/X86InstrInfo.td index f40847f1e4..4482da7d4b 100644 --- a/lib/Target/X86/X86InstrInfo.td +++ b/lib/Target/X86/X86InstrInfo.td @@ -245,6 +245,12 @@ def extloadi16i8 : PatFrag<(ops node:$ptr), (i16 (extloadi8 node:$ptr))>; def extloadi32i8 : PatFrag<(ops node:$ptr), (i32 (extloadi8 node:$ptr))>; def extloadi32i16 : PatFrag<(ops node:$ptr), (i32 (extloadi16 node:$ptr))>; + +// An 'and' node with a single use. +def and_su : PatFrag<(ops node:$lhs, node:$rhs), (and node:$lhs, node:$rhs), [{ + return N->hasOneUse(); +}]>; + //===----------------------------------------------------------------------===// // Instruction list... // @@ -2078,16 +2084,16 @@ let Defs = [EFLAGS] in { let isCommutable = 1 in { // TEST X, Y --> TEST Y, X def TEST8rr : I<0x84, MRMDestReg, (outs), (ins GR8:$src1, GR8:$src2), "test{b}\t{$src2, $src1|$src1, $src2}", - [(X86cmp (and GR8:$src1, GR8:$src2), 0), + [(X86cmp (and_su GR8:$src1, GR8:$src2), 0), (implicit EFLAGS)]>; def TEST16rr : I<0x85, MRMDestReg, (outs), (ins GR16:$src1, GR16:$src2), "test{w}\t{$src2, $src1|$src1, $src2}", - [(X86cmp (and GR16:$src1, GR16:$src2), 0), + [(X86cmp (and_su GR16:$src1, GR16:$src2), 0), (implicit EFLAGS)]>, OpSize; def TEST32rr : I<0x85, MRMDestReg, (outs), (ins GR32:$src1, GR32:$src2), "test{l}\t{$src2, $src1|$src1, $src2}", - [(X86cmp (and GR32:$src1, GR32:$src2), 0), + [(X86cmp (and_su GR32:$src1, GR32:$src2), 0), (implicit EFLAGS)]>; } @@ -2107,17 +2113,17 @@ def TEST32rm : I<0x85, MRMSrcMem, (outs), (ins GR32:$src1, i32mem:$src2), def TEST8ri : Ii8 <0xF6, MRM0r, // flags = GR8 & imm8 (outs), (ins GR8:$src1, i8imm:$src2), "test{b}\t{$src2, $src1|$src1, $src2}", - [(X86cmp (and GR8:$src1, imm:$src2), 0), + [(X86cmp (and_su GR8:$src1, imm:$src2), 0), (implicit EFLAGS)]>; def TEST16ri : Ii16<0xF7, MRM0r, // flags = GR16 & imm16 (outs), (ins GR16:$src1, i16imm:$src2), "test{w}\t{$src2, $src1|$src1, $src2}", - [(X86cmp (and GR16:$src1, imm:$src2), 0), + [(X86cmp (and_su GR16:$src1, imm:$src2), 0), (implicit EFLAGS)]>, OpSize; def TEST32ri : Ii32<0xF7, MRM0r, // flags = GR32 & imm32 (outs), (ins GR32:$src1, i32imm:$src2), "test{l}\t{$src2, $src1|$src1, $src2}", - [(X86cmp (and GR32:$src1, imm:$src2), 0), + [(X86cmp (and_su GR32:$src1, imm:$src2), 0), (implicit EFLAGS)]>; def TEST8mi : Ii8 <0xF6, MRM0m, // flags = [mem8] & imm8 diff --git a/test/CodeGen/X86/test-nofold.ll b/test/CodeGen/X86/test-nofold.ll new file mode 100644 index 0000000000..a24a9a0940 --- /dev/null +++ b/test/CodeGen/X86/test-nofold.ll @@ -0,0 +1,29 @@ +; RUN: llvm-as < %s | llc -march=x86 -mcpu=yonah | grep {testl.*%e.x.*%e.x} +; rdar://5752025 + +; We don't want to fold the and into the test, because the and clobbers its +; input forcing a copy. We want: +; movl $15, %ecx +; andl 4(%esp), %ecx +; testl %ecx, %ecx +; movl $42, %eax +; cmove %ecx, %eax +; ret +; +; Not: +; movl 4(%esp), %eax +; movl %eax, %ecx +; andl $15, %ecx +; testl $15, %eax +; movl $42, %eax +; cmove %ecx, %eax +; ret + +define i32 @t1(i32 %X) nounwind { +entry: + %tmp2 = and i32 %X, 15 ; <i32> [#uses=2] + %tmp4 = icmp eq i32 %tmp2, 0 ; <i1> [#uses=1] + %retval = select i1 %tmp4, i32 %tmp2, i32 42 ; <i32> [#uses=1] + ret i32 %retval +} + |