7 Commits

Author	SHA1	Message	Date
Jakob Stoklund Olesen	7ee3ca10f5	Revert remaining part of r93200: "Disable folding sext(trunc(x)) -> x" ... This fixes PR5997. These transforms were disabled because codegen couldn't deal with other uses of trunc(x). This is now handled by the peephole pass. This causes no regressions on x86-64. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159003 91177308-0d34-0410-b5e6-96231b3b80d8	2012-06-22 16:36:43 +00:00
Chris Lattner	7a6aa1a391	Enhance a bunch of transformations in instcombine to start generating ... exact/nsw/nuw shifts and have instcombine infer them when it can prove that the relevant properties are true for a given shift without them. Also, a variety of refactoring to use the new patternmatch logic thrown in for good luck. I believe that this takes care of a bunch of related code quality issues attached to PR8862. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125267 91177308-0d34-0410-b5e6-96231b3b80d8	2011-02-10 05:36:31 +00:00
Chris Lattner	62fe406dc2	implement an instcombine xform that canonicalizes casts outside of and-with-constant operations. ... This fixes rdar://8808586 which observed that we used to compile: union xy { struct x { _Bool b[15]; } x; __attribute__((packed)) struct y { __attribute__((packed)) unsigned long b0to7; __attribute__((packed)) unsigned int b8to11; __attribute__((packed)) unsigned short b12to13; __attribute__((packed)) unsigned char b14; } y; }; struct x foo(union xy *xy) { return xy->x; } into: _foo: ## @foo movq (%rdi), %rax movabsq $1095216660480, %rcx ## imm = 0xFF00000000 andq %rax, %rcx movabsq $-72057594037927936, %rdx ## imm = 0xFF00000000000000 andq %rax, %rdx movzbl %al, %esi orq %rdx, %rsi movq %rax, %rdx andq $65280, %rdx ## imm = 0xFF00 orq %rsi, %rdx movq %rax, %rsi andq $16711680, %rsi ## imm = 0xFF0000 orq %rdx, %rsi movl %eax, %edx andl $-16777216, %edx ## imm = 0xFFFFFFFFFF000000 orq %rsi, %rdx orq %rcx, %rdx movabsq $280375465082880, %rcx ## imm = 0xFF0000000000 movq %rax, %rsi andq %rcx, %rsi orq %rdx, %rsi movabsq $71776119061217280, %r8 ## imm = 0xFF000000000000 andq %r8, %rax orq %rsi, %rax movzwl 12(%rdi), %edx movzbl 14(%rdi), %esi shlq $16, %rsi orl %edx, %esi movq %rsi, %r9 shlq $32, %r9 movl 8(%rdi), %edx orq %r9, %rdx andq %rdx, %rcx movzbl %sil, %esi shlq $32, %rsi orq %rcx, %rsi movl %edx, %ecx andl $-16777216, %ecx ## imm = 0xFFFFFFFFFF000000 orq %rsi, %rcx movq %rdx, %rsi andq $16711680, %rsi ## imm = 0xFF0000 orq %rcx, %rsi movq %rdx, %rcx andq $65280, %rcx ## imm = 0xFF00 orq %rsi, %rcx movzbl %dl, %esi orq %rcx, %rsi andq %r8, %rdx orq %rsi, %rdx ret We now compile this into: _foo: ## @foo ## BB#0: ## %entry movzwl 12(%rdi), %eax movzbl 14(%rdi), %ecx shlq $16, %rcx orl %eax, %ecx shlq $32, %rcx movl 8(%rdi), %edx orq %rcx, %rdx movq (%rdi), %rax ret A small improvement :-) git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123520 91177308-0d34-0410-b5e6-96231b3b80d8	2011-01-15 06:32:33 +00:00
Chris Lattner	f9d05ab007	teach the truncation optimization that an entire chain of ... computation can be truncated if it is fed by a sext/zext that doesn't have to be exactly equal to the truncation result type. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112285 91177308-0d34-0410-b5e6-96231b3b80d8	2010-08-27 20:32:06 +00:00
Chris Lattner	784f333aef	Add an instcombine to clean up a common pattern produced ... by the SRoA "promote to large integer" code, eliminating some type conversions like this: %94 = zext i16 %93 to i32 ; <i32> [#uses=2] %96 = lshr i32 %94, 8 ; <i32> [#uses=1] %101 = trunc i32 %96 to i8 ; <i8> [#uses=1] This also unblocks other xforms from happening, now clang is able to compile: struct S { float A, B, C, D; }; float foo(struct S A) { return A.A + A.B+A.C+A.D; } into: _foo: ## @foo ## BB#0: ## %entry pshufd $1, %xmm0, %xmm2 addss %xmm0, %xmm2 movdqa %xmm1, %xmm3 addss %xmm2, %xmm3 pshufd $1, %xmm1, %xmm0 addss %xmm3, %xmm0 ret on x86-64, instead of: _foo: ## @foo ## BB#0: ## %entry movd %xmm0, %rax shrq $32, %rax movd %eax, %xmm2 addss %xmm0, %xmm2 movapd %xmm1, %xmm3 addss %xmm2, %xmm3 movd %xmm1, %rax shrq $32, %rax movd %eax, %xmm0 addss %xmm3, %xmm0 ret This seems pretty close to optimal to me, at least without using horizontal adds. This also triggers in lots of other code, including SPEC. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112278 91177308-0d34-0410-b5e6-96231b3b80d8	2010-08-27 18:31:05 +00:00
Chris Lattner	98b3d3793c	filecheckize ... git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112235 91177308-0d34-0410-b5e6-96231b3b80d8	2010-08-26 22:23:39 +00:00
Chris Lattner	681ccf40d7	rename test. ... git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112234 91177308-0d34-0410-b5e6-96231b3b80d8	2010-08-26 22:20:47 +00:00