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2a46e4c020
- Factor out code to query and modify the sign bit of a floatingpoint value as an integer. This also works if none of the targets integer types is big enough to hold all bits of the floatingpoint value. - Legalize FABS(x) as FCOPYSIGN(x, 0.0) if FCOPYSIGN is available, otherwise perform bit manipulation on the sign bit. The previous code used "x >u 0 ? x : -x" which is incorrect for x being -0.0! It also takes 34 instructions on ARM Cortex-M4. With this patch we only require 5: vldr d0, LCPI0_0 vmov r2, r3, d0 lsrs r2, r3, #31 bfi r1, r2, #31, #1 bx lr (This could be further improved if the compiler would recognize that r2, r3 is zero). - Only lower FCOPYSIGN(x, y) = sign(x) ? -FABS(x) : FABS(x) if FABS is available otherwise perform bit manipulation on the sign bit. - Perform the sign(x) test by masking out the sign bit and comparing with 0 rather than shifting the sign bit to the highest position and testing for "<s 0". For x86 copysignl (on 80bit values) this gets us: testl $32768, %eax rather than: shlq $48, %rax sets %al testb %al, %al git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242107 91177308-0d34-0410-b5e6-96231b3b80d8 |
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Analysis | ||
AsmParser | ||
Bitcode | ||
CodeGen | ||
DebugInfo | ||
ExecutionEngine | ||
Fuzzer | ||
IR | ||
IRReader | ||
LibDriver | ||
LineEditor | ||
Linker | ||
LTO | ||
MC | ||
Object | ||
Option | ||
Passes | ||
ProfileData | ||
Support | ||
TableGen | ||
Target | ||
Transforms | ||
CMakeLists.txt | ||
LLVMBuild.txt | ||
Makefile |