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llvm-project/llvm/test/Transforms/GVN/rle-phi-translate.ll

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convert to filecheck llvm-svn: 89977
2009-11-27 07:32:59 +08:00
; RUN: opt < %s -gvn -S | FileCheck %s
Implement initial support for PHI translation in memdep. This means that memdep keeps track of how PHIs affect the pointer in dep queries, which allows it to eliminate the load in cases like rle-phi-translate.ll, which basically end up being: BB1: X = load P br BB3 BB2: Y = load Q br BB3 BB3: R = phi [P] [Q] load R turning "load R" into a phi of X/Y. In addition to additional exposed opportunities, this makes memdep safe in many cases that it wasn't before (which is required for load PRE) and also makes it substantially more efficient. For example, consider: bb1: // has many predecessors. P = some_operator() load P In this example, previously memdep would scan all the predecessors of BB1 to see if they had something that would mustalias P. In some cases (e.g. test/Transforms/GVN/rle-must-alias.ll) it would actually find them and end up eliminating something. In many other cases though, it would scan and not find anything useful. MemDep now stops at a block if the pointer is defined in that block and cannot be phi translated to predecessors. This causes it to miss the (rare) cases like rle-must-alias.ll, but makes it faster by not scanning tons of stuff that is unlikely to be useful. For example, this speeds up GVN as a whole from 3.928s to 2.448s (60%)!. IMO, scalar GVN should be enhanced to simplify the rle-must-alias pointer base anyway, which would allow the loads to be eliminated. In the future, this should be enhanced to phi translate through geps and bitcasts as well (as indicated by FIXMEs) making memdep even more powerful. llvm-svn: 61022
2008-12-15 11:35:32 +08:00
target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
target triple = "i386-apple-darwin7"
convert to filecheck llvm-svn: 89977
2009-11-27 07:32:59 +08:00
define i32 @test1(i32* %b, i32* %c) nounwind {
Teach memdep to phi translate bitcasts. This allows us to compile the example in GCC PR16799 to: LBB1_2: ## %bb1 movl %eax, %eax subq %rax, %rdi movq %rdi, (%rcx) movl (%rdi), %eax testl %eax, %eax je LBB1_2 instead of: LBB1_2: ## %bb1 movl (%rdi), %ecx subq %rcx, %rdi movq %rdi, (%rax) cmpl $0, (%rdi) je LBB1_2 llvm-svn: 89978
2009-11-27 07:41:07 +08:00
; CHECK: @test1
Implement initial support for PHI translation in memdep. This means that memdep keeps track of how PHIs affect the pointer in dep queries, which allows it to eliminate the load in cases like rle-phi-translate.ll, which basically end up being: BB1: X = load P br BB3 BB2: Y = load Q br BB3 BB3: R = phi [P] [Q] load R turning "load R" into a phi of X/Y. In addition to additional exposed opportunities, this makes memdep safe in many cases that it wasn't before (which is required for load PRE) and also makes it substantially more efficient. For example, consider: bb1: // has many predecessors. P = some_operator() load P In this example, previously memdep would scan all the predecessors of BB1 to see if they had something that would mustalias P. In some cases (e.g. test/Transforms/GVN/rle-must-alias.ll) it would actually find them and end up eliminating something. In many other cases though, it would scan and not find anything useful. MemDep now stops at a block if the pointer is defined in that block and cannot be phi translated to predecessors. This causes it to miss the (rare) cases like rle-must-alias.ll, but makes it faster by not scanning tons of stuff that is unlikely to be useful. For example, this speeds up GVN as a whole from 3.928s to 2.448s (60%)!. IMO, scalar GVN should be enhanced to simplify the rle-must-alias pointer base anyway, which would allow the loads to be eliminated. In the future, this should be enhanced to phi translate through geps and bitcasts as well (as indicated by FIXMEs) making memdep even more powerful. llvm-svn: 61022
2008-12-15 11:35:32 +08:00
entry:
convert to filecheck llvm-svn: 89977
2009-11-27 07:32:59 +08:00
%g = alloca i32
%t1 = icmp eq i32* %b, null
Implement initial support for PHI translation in memdep. This means that memdep keeps track of how PHIs affect the pointer in dep queries, which allows it to eliminate the load in cases like rle-phi-translate.ll, which basically end up being: BB1: X = load P br BB3 BB2: Y = load Q br BB3 BB3: R = phi [P] [Q] load R turning "load R" into a phi of X/Y. In addition to additional exposed opportunities, this makes memdep safe in many cases that it wasn't before (which is required for load PRE) and also makes it substantially more efficient. For example, consider: bb1: // has many predecessors. P = some_operator() load P In this example, previously memdep would scan all the predecessors of BB1 to see if they had something that would mustalias P. In some cases (e.g. test/Transforms/GVN/rle-must-alias.ll) it would actually find them and end up eliminating something. In many other cases though, it would scan and not find anything useful. MemDep now stops at a block if the pointer is defined in that block and cannot be phi translated to predecessors. This causes it to miss the (rare) cases like rle-must-alias.ll, but makes it faster by not scanning tons of stuff that is unlikely to be useful. For example, this speeds up GVN as a whole from 3.928s to 2.448s (60%)!. IMO, scalar GVN should be enhanced to simplify the rle-must-alias pointer base anyway, which would allow the loads to be eliminated. In the future, this should be enhanced to phi translate through geps and bitcasts as well (as indicated by FIXMEs) making memdep even more powerful. llvm-svn: 61022
2008-12-15 11:35:32 +08:00
br i1 %t1, label %bb, label %bb1
convert to filecheck llvm-svn: 89977
2009-11-27 07:32:59 +08:00
bb:
%t2 = load i32* %c, align 4
%t3 = add i32 %t2, 1
Implement initial support for PHI translation in memdep. This means that memdep keeps track of how PHIs affect the pointer in dep queries, which allows it to eliminate the load in cases like rle-phi-translate.ll, which basically end up being: BB1: X = load P br BB3 BB2: Y = load Q br BB3 BB3: R = phi [P] [Q] load R turning "load R" into a phi of X/Y. In addition to additional exposed opportunities, this makes memdep safe in many cases that it wasn't before (which is required for load PRE) and also makes it substantially more efficient. For example, consider: bb1: // has many predecessors. P = some_operator() load P In this example, previously memdep would scan all the predecessors of BB1 to see if they had something that would mustalias P. In some cases (e.g. test/Transforms/GVN/rle-must-alias.ll) it would actually find them and end up eliminating something. In many other cases though, it would scan and not find anything useful. MemDep now stops at a block if the pointer is defined in that block and cannot be phi translated to predecessors. This causes it to miss the (rare) cases like rle-must-alias.ll, but makes it faster by not scanning tons of stuff that is unlikely to be useful. For example, this speeds up GVN as a whole from 3.928s to 2.448s (60%)!. IMO, scalar GVN should be enhanced to simplify the rle-must-alias pointer base anyway, which would allow the loads to be eliminated. In the future, this should be enhanced to phi translate through geps and bitcasts as well (as indicated by FIXMEs) making memdep even more powerful. llvm-svn: 61022
2008-12-15 11:35:32 +08:00
store i32 %t3, i32* %g, align 4
br label %bb2
bb1: ; preds = %entry
convert to filecheck llvm-svn: 89977
2009-11-27 07:32:59 +08:00
%t5 = load i32* %b, align 4
%t6 = add i32 %t5, 1
Implement initial support for PHI translation in memdep. This means that memdep keeps track of how PHIs affect the pointer in dep queries, which allows it to eliminate the load in cases like rle-phi-translate.ll, which basically end up being: BB1: X = load P br BB3 BB2: Y = load Q br BB3 BB3: R = phi [P] [Q] load R turning "load R" into a phi of X/Y. In addition to additional exposed opportunities, this makes memdep safe in many cases that it wasn't before (which is required for load PRE) and also makes it substantially more efficient. For example, consider: bb1: // has many predecessors. P = some_operator() load P In this example, previously memdep would scan all the predecessors of BB1 to see if they had something that would mustalias P. In some cases (e.g. test/Transforms/GVN/rle-must-alias.ll) it would actually find them and end up eliminating something. In many other cases though, it would scan and not find anything useful. MemDep now stops at a block if the pointer is defined in that block and cannot be phi translated to predecessors. This causes it to miss the (rare) cases like rle-must-alias.ll, but makes it faster by not scanning tons of stuff that is unlikely to be useful. For example, this speeds up GVN as a whole from 3.928s to 2.448s (60%)!. IMO, scalar GVN should be enhanced to simplify the rle-must-alias pointer base anyway, which would allow the loads to be eliminated. In the future, this should be enhanced to phi translate through geps and bitcasts as well (as indicated by FIXMEs) making memdep even more powerful. llvm-svn: 61022
2008-12-15 11:35:32 +08:00
store i32 %t6, i32* %g, align 4
br label %bb2
bb2: ; preds = %bb1, %bb
convert to filecheck llvm-svn: 89977
2009-11-27 07:32:59 +08:00
%c_addr.0 = phi i32* [ %g, %bb1 ], [ %c, %bb ]
%b_addr.0 = phi i32* [ %b, %bb1 ], [ %g, %bb ]
%cv = load i32* %c_addr.0, align 4
%bv = load i32* %b_addr.0, align 4
; CHECK: %bv = phi i32
; CHECK: %cv = phi i32
; CHECK-NOT: load
; CHECK: ret i32
%ret = add i32 %cv, %bv
Implement initial support for PHI translation in memdep. This means that memdep keeps track of how PHIs affect the pointer in dep queries, which allows it to eliminate the load in cases like rle-phi-translate.ll, which basically end up being: BB1: X = load P br BB3 BB2: Y = load Q br BB3 BB3: R = phi [P] [Q] load R turning "load R" into a phi of X/Y. In addition to additional exposed opportunities, this makes memdep safe in many cases that it wasn't before (which is required for load PRE) and also makes it substantially more efficient. For example, consider: bb1: // has many predecessors. P = some_operator() load P In this example, previously memdep would scan all the predecessors of BB1 to see if they had something that would mustalias P. In some cases (e.g. test/Transforms/GVN/rle-must-alias.ll) it would actually find them and end up eliminating something. In many other cases though, it would scan and not find anything useful. MemDep now stops at a block if the pointer is defined in that block and cannot be phi translated to predecessors. This causes it to miss the (rare) cases like rle-must-alias.ll, but makes it faster by not scanning tons of stuff that is unlikely to be useful. For example, this speeds up GVN as a whole from 3.928s to 2.448s (60%)!. IMO, scalar GVN should be enhanced to simplify the rle-must-alias pointer base anyway, which would allow the loads to be eliminated. In the future, this should be enhanced to phi translate through geps and bitcasts as well (as indicated by FIXMEs) making memdep even more powerful. llvm-svn: 61022
2008-12-15 11:35:32 +08:00
ret i32 %ret
}
Teach memdep to phi translate bitcasts. This allows us to compile the example in GCC PR16799 to: LBB1_2: ## %bb1 movl %eax, %eax subq %rax, %rdi movq %rdi, (%rcx) movl (%rdi), %eax testl %eax, %eax je LBB1_2 instead of: LBB1_2: ## %bb1 movl (%rdi), %ecx subq %rcx, %rdi movq %rdi, (%rax) cmpl $0, (%rdi) je LBB1_2 llvm-svn: 89978
2009-11-27 07:41:07 +08:00
define i8 @test2(i1 %cond, i32* %b, i32* %c) nounwind {
; CHECK: @test2
entry:
br i1 %cond, label %bb, label %bb1
bb:
%b1 = bitcast i32* %b to i8*
store i8 4, i8* %b1
br label %bb2
bb1:
%c1 = bitcast i32* %c to i8*
store i8 92, i8* %c1
br label %bb2
bb2:
%d = phi i32* [ %c, %bb1 ], [ %b, %bb ]
%d1 = bitcast i32* %d to i8*
%dv = load i8* %d1
teach memdep to do trivial PHI translation of GEPs. More to come. llvm-svn: 89979
2009-11-27 08:07:37 +08:00
; CHECK: %dv = phi i8 [ 92, %bb1 ], [ 4, %bb ]
Teach memdep to phi translate bitcasts. This allows us to compile the example in GCC PR16799 to: LBB1_2: ## %bb1 movl %eax, %eax subq %rax, %rdi movq %rdi, (%rcx) movl (%rdi), %eax testl %eax, %eax je LBB1_2 instead of: LBB1_2: ## %bb1 movl (%rdi), %ecx subq %rcx, %rdi movq %rdi, (%rax) cmpl $0, (%rdi) je LBB1_2 llvm-svn: 89978
2009-11-27 07:41:07 +08:00
; CHECK-NOT: load
; CHECK: ret i8 %dv
ret i8 %dv
}
teach memdep to do trivial PHI translation of GEPs. More to come. llvm-svn: 89979
2009-11-27 08:07:37 +08:00
define i32 @test3(i1 %cond, i32* %b, i32* %c) nounwind {
; CHECK: @test3
entry:
br i1 %cond, label %bb, label %bb1
bb:
%b1 = getelementptr i32* %b, i32 17
store i32 4, i32* %b1
br label %bb2
bb1:
%c1 = getelementptr i32* %c, i32 7
store i32 82, i32* %c1
br label %bb2
bb2:
%d = phi i32* [ %c, %bb1 ], [ %b, %bb ]
%i = phi i32 [ 7, %bb1 ], [ 17, %bb ]
%d1 = getelementptr i32* %d, i32 %i
%dv = load i32* %d1
redisable this, my bootstrap worked because it wasn't an optimized build, whoops. llvm-svn: 89991
2009-11-27 13:53:01 +08:00
; HECK: %dv = phi i32 [ 82, %bb1 ], [ 4, %bb ]
; HECK-NOT: load
; HECK: ret i32 %dv
teach memdep to do trivial PHI translation of GEPs. More to come. llvm-svn: 89979
2009-11-27 08:07:37 +08:00
ret i32 %dv
}
teach phi translation of GEPs to simplify geps like 'gep x, 0'. This allows us to compile the example from PR5313 into: LBB1_2: ## %bb incl %ecx movb %al, (%rsi) movslq %ecx, %rax movb (%rdi,%rax), %al testb %al, %al jne LBB1_2 instead of: LBB1_2: ## %bb movslq %eax, %rcx incl %eax movb (%rdi,%rcx), %cl movb %cl, (%rsi) movslq %eax, %rcx cmpb $0, (%rdi,%rcx) jne LBB1_2 llvm-svn: 89981
2009-11-27 08:34:38 +08:00
; PR5313
define i32 @test4(i1 %cond, i32* %b, i32* %c) nounwind {
; CHECK: @test4
entry:
br i1 %cond, label %bb, label %bb1
bb:
store i32 4, i32* %b
br label %bb2
bb1:
%c1 = getelementptr i32* %c, i32 7
store i32 82, i32* %c1
br label %bb2
bb2:
%d = phi i32* [ %c, %bb1 ], [ %b, %bb ]
%i = phi i32 [ 7, %bb1 ], [ 0, %bb ]
%d1 = getelementptr i32* %d, i32 %i
%dv = load i32* %d1
redisable this, my bootstrap worked because it wasn't an optimized build, whoops. llvm-svn: 89991
2009-11-27 13:53:01 +08:00
; HECK: %dv = phi i32 [ 82, %bb1 ], [ 4, %bb ]
; HECK-NOT: load
; HECK: ret i32 %dv
teach phi translation of GEPs to simplify geps like 'gep x, 0'. This allows us to compile the example from PR5313 into: LBB1_2: ## %bb incl %ecx movb %al, (%rsi) movslq %ecx, %rax movb (%rdi,%rax), %al testb %al, %al jne LBB1_2 instead of: LBB1_2: ## %bb movslq %eax, %rcx incl %eax movb (%rdi,%rcx), %cl movb %cl, (%rsi) movslq %eax, %rcx cmpb $0, (%rdi,%rcx) jne LBB1_2 llvm-svn: 89981
2009-11-27 08:34:38 +08:00
ret i32 %dv
}