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llvm-6502/test/Transforms/InstSimplify/2011-01-18-Compare.ll

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At -O123 the early-cse pass is run before instcombine has run. According to my auto-simplier the transform most missed by early-cse is (zext X) != 0 -> X != 0. This patch adds this transform and some related logic to InstructionSimplify and removes some of the logic from instcombine (unfortunately not all because there are several situations in which instcombine can improve things by making new instructions, whereas instsimplify is not allowed to do this). At -O2 this often results in more than 15% more simplifications by early-cse, and results in hundreds of lines of bitcode being eliminated from the testsuite. I did see some small negative effects in the testsuite, for example a few additional instructions in three programs. One program, 483.xalancbmk, got an additional 35 instructions, which seems to be due to a function getting an additional instruction and then being inlined all over the place. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123911 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-20 13:21:55 +00:00
; RUN: opt < %s -instsimplify -S | FileCheck %s
target datalayout = "p:32:32"
define i1 @ptrtoint() {
; CHECK: @ptrtoint
%a = alloca i8
%tmp = ptrtoint i8* %a to i32
%r = icmp eq i32 %tmp, 0
ret i1 %r
; CHECK: ret i1 false
}
define i1 @zext(i32 %x) {
; CHECK: @zext
%e1 = zext i32 %x to i64
%e2 = zext i32 %x to i64
%r = icmp eq i64 %e1, %e2
ret i1 %r
; CHECK: ret i1 true
}
define i1 @zext2(i1 %x) {
; CHECK: @zext2
%e = zext i1 %x to i32
%c = icmp ne i32 %e, 0
ret i1 %c
; CHECK: ret i1 %x
}
According to my auto-simplifier the most common missed simplifications in optimized code are: (non-negative number)+(power-of-two) != 0 -> true and (x | 1) != 0 -> true Instcombine knows about the second one of course, but only does it if X|1 has only one use. These fire thousands of times in the testsuite. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124183 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-25 09:38:29 +00:00
define i1 @zext3() {
; CHECK: @zext3
%e = zext i1 1 to i32
%c = icmp ne i32 %e, 0
ret i1 %c
; CHECK: ret i1 true
}
At -O123 the early-cse pass is run before instcombine has run. According to my auto-simplier the transform most missed by early-cse is (zext X) != 0 -> X != 0. This patch adds this transform and some related logic to InstructionSimplify and removes some of the logic from instcombine (unfortunately not all because there are several situations in which instcombine can improve things by making new instructions, whereas instsimplify is not allowed to do this). At -O2 this often results in more than 15% more simplifications by early-cse, and results in hundreds of lines of bitcode being eliminated from the testsuite. I did see some small negative effects in the testsuite, for example a few additional instructions in three programs. One program, 483.xalancbmk, got an additional 35 instructions, which seems to be due to a function getting an additional instruction and then being inlined all over the place. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123911 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-20 13:21:55 +00:00
define i1 @sext(i32 %x) {
; CHECK: @sext
%e1 = sext i32 %x to i64
%e2 = sext i32 %x to i64
%r = icmp eq i64 %e1, %e2
ret i1 %r
; CHECK: ret i1 true
}
define i1 @sext2(i1 %x) {
; CHECK: @sext2
%e = sext i1 %x to i32
%c = icmp ne i32 %e, 0
ret i1 %c
; CHECK: ret i1 %x
}
According to my auto-simplifier the most common missed simplifications in optimized code are: (non-negative number)+(power-of-two) != 0 -> true and (x | 1) != 0 -> true Instcombine knows about the second one of course, but only does it if X|1 has only one use. These fire thousands of times in the testsuite. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124183 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-25 09:38:29 +00:00
define i1 @sext3() {
; CHECK: @sext3
%e = sext i1 1 to i32
%c = icmp ne i32 %e, 0
ret i1 %c
; CHECK: ret i1 true
}
define i1 @add(i32 %x, i32 %y) {
In which I discover that zero+zero is zero, d'oh! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124188 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-25 15:14:15 +00:00
; CHECK: @add
According to my auto-simplifier the most common missed simplifications in optimized code are: (non-negative number)+(power-of-two) != 0 -> true and (x | 1) != 0 -> true Instcombine knows about the second one of course, but only does it if X|1 has only one use. These fire thousands of times in the testsuite. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124183 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-25 09:38:29 +00:00
%l = lshr i32 %x, 1
In which I discover that zero+zero is zero, d'oh! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124188 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-25 15:14:15 +00:00
%q = lshr i32 %y, 1
%r = or i32 %q, 1
According to my auto-simplifier the most common missed simplifications in optimized code are: (non-negative number)+(power-of-two) != 0 -> true and (x | 1) != 0 -> true Instcombine knows about the second one of course, but only does it if X|1 has only one use. These fire thousands of times in the testsuite. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124183 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-25 09:38:29 +00:00
%s = add i32 %l, %r
%c = icmp eq i32 %s, 0
ret i1 %c
In which I discover that zero+zero is zero, d'oh! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124188 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-25 15:14:15 +00:00
; CHECK: ret i1 false
According to my auto-simplifier the most common missed simplifications in optimized code are: (non-negative number)+(power-of-two) != 0 -> true and (x | 1) != 0 -> true Instcombine knows about the second one of course, but only does it if X|1 has only one use. These fire thousands of times in the testsuite. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124183 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-25 09:38:29 +00:00
}
define i1 @add2(i8 %x, i8 %y) {
; CHECK: @add2
%l = or i8 %x, 128
%r = or i8 %y, 129
%s = add i8 %l, %r
%c = icmp eq i8 %s, 0
ret i1 %c
; CHECK: ret i1 false
}
In which I discover that zero+zero is zero, d'oh! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124188 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-25 15:14:15 +00:00
define i1 @add3(i8 %x, i8 %y) {
; CHECK: @add3
%l = zext i8 %x to i32
%r = zext i8 %y to i32
%s = add i32 %l, %r
%c = icmp eq i32 %s, 0
ret i1 %c
; CHECK: ret i1 %c
}
According to my auto-simplifier the most common missed simplifications in optimized code are: (non-negative number)+(power-of-two) != 0 -> true and (x | 1) != 0 -> true Instcombine knows about the second one of course, but only does it if X|1 has only one use. These fire thousands of times in the testsuite. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124183 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-25 09:38:29 +00:00
define i1 @addpowtwo(i32 %x, i32 %y) {
; CHECK: @addpowtwo
%l = lshr i32 %x, 1
%r = shl i32 1, %y
%s = add i32 %l, %r
%c = icmp eq i32 %s, 0
ret i1 %c
; CHECK: ret i1 false
}
define i1 @or(i32 %x) {
; CHECK: @or
%o = or i32 %x, 1
%c = icmp eq i32 %o, 0
ret i1 %c
; CHECK: ret i1 false
}
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