diff options
| -rw-r--r-- | llvm/lib/Transforms/Utils/BypassSlowDivision.cpp | 9 | ||||
| -rw-r--r-- | llvm/test/CodeGen/X86/divide-by-constant.ll | 94 |
2 files changed, 35 insertions, 68 deletions
diff --git a/llvm/lib/Transforms/Utils/BypassSlowDivision.cpp b/llvm/lib/Transforms/Utils/BypassSlowDivision.cpp index 05512a6dff3..e7828af648a 100644 --- a/llvm/lib/Transforms/Utils/BypassSlowDivision.cpp +++ b/llvm/lib/Transforms/Utils/BypassSlowDivision.cpp @@ -388,6 +388,15 @@ Optional<QuotRemPair> FastDivInsertionTask::insertFastDivAndRem() { return None; } + // After Constant Hoisting pass, long constants may be represented as + // bitcast instructions. As a result, some constants may look like an + // instruction at first, and an additional check is necessary to find out if + // an operand is actually a constant. + if (auto *BCI = dyn_cast<BitCastInst>(Divisor)) + if (BCI->getParent() == SlowDivOrRem->getParent() && + isa<ConstantInt>(BCI->getOperand(0))) + return None; + if (DividendShort && !isSignedOp()) { // If the division is unsigned and Dividend is known to be short, then // either diff --git a/llvm/test/CodeGen/X86/divide-by-constant.ll b/llvm/test/CodeGen/X86/divide-by-constant.ll index 0c29edf4840..00a0e31ea0d 100644 --- a/llvm/test/CodeGen/X86/divide-by-constant.ll +++ b/llvm/test/CodeGen/X86/divide-by-constant.ll @@ -384,39 +384,18 @@ define { i64, i32 } @PR38622(i64) nounwind { ; X32-NEXT: popl %ebp ; X32-NEXT: retl ; -; X64-FAST-LABEL: PR38622: -; X64-FAST: # %bb.0: -; X64-FAST-NEXT: movq %rdi, %rax -; X64-FAST-NEXT: shrq $11, %rax -; X64-FAST-NEXT: movabsq $4835703278458517, %rcx # imm = 0x112E0BE826D695 -; X64-FAST-NEXT: mulq %rcx -; X64-FAST-NEXT: shrq $9, %rdx -; X64-FAST-NEXT: imull $-294967296, %edx, %eax # imm = 0xEE6B2800 -; X64-FAST-NEXT: subl %eax, %edi -; X64-FAST-NEXT: movq %rdx, %rax -; X64-FAST-NEXT: movl %edi, %edx -; X64-FAST-NEXT: retq -; -; X64-SLOW-LABEL: PR38622: -; X64-SLOW: # %bb.0: -; X64-SLOW-NEXT: movl $4000000000, %ecx # imm = 0xEE6B2800 -; X64-SLOW-NEXT: movq %rdi, %rax -; X64-SLOW-NEXT: shrq $32, %rax -; X64-SLOW-NEXT: je .LBB14_1 -; X64-SLOW-NEXT: # %bb.2: -; X64-SLOW-NEXT: xorl %edx, %edx -; X64-SLOW-NEXT: movq %rdi, %rax -; X64-SLOW-NEXT: divq %rcx -; X64-SLOW-NEXT: # kill: def $edx killed $edx killed $rdx -; X64-SLOW-NEXT: retq -; X64-SLOW-NEXT: .LBB14_1: -; X64-SLOW-NEXT: xorl %edx, %edx -; X64-SLOW-NEXT: movl %edi, %eax -; X64-SLOW-NEXT: divl %ecx -; X64-SLOW-NEXT: # kill: def $edx killed $edx def $rdx -; X64-SLOW-NEXT: # kill: def $eax killed $eax def $rax -; X64-SLOW-NEXT: # kill: def $edx killed $edx killed $rdx -; X64-SLOW-NEXT: retq +; X64-LABEL: PR38622: +; X64: # %bb.0: +; X64-NEXT: movq %rdi, %rax +; X64-NEXT: shrq $11, %rax +; X64-NEXT: movabsq $4835703278458517, %rcx # imm = 0x112E0BE826D695 +; X64-NEXT: mulq %rcx +; X64-NEXT: shrq $9, %rdx +; X64-NEXT: imull $-294967296, %edx, %eax # imm = 0xEE6B2800 +; X64-NEXT: subl %eax, %edi +; X64-NEXT: movq %rdx, %rax +; X64-NEXT: movl %edi, %edx +; X64-NEXT: retq %2 = udiv i64 %0, 4000000000 %3 = urem i64 %0, 4000000000 %4 = trunc i64 %3 to i32 @@ -459,41 +438,20 @@ define { i64, i32 } @PR38622_signed(i64) nounwind { ; X32-NEXT: popl %ebp ; X32-NEXT: retl ; -; X64-FAST-LABEL: PR38622_signed: -; X64-FAST: # %bb.0: -; X64-FAST-NEXT: movabsq $1237940039285380275, %rcx # imm = 0x112E0BE826D694B3 -; X64-FAST-NEXT: movq %rdi, %rax -; X64-FAST-NEXT: imulq %rcx -; X64-FAST-NEXT: movq %rdx, %rcx -; X64-FAST-NEXT: shrq $63, %rcx -; X64-FAST-NEXT: sarq $28, %rdx -; X64-FAST-NEXT: leaq (%rdx,%rcx), %rax -; X64-FAST-NEXT: addl %ecx, %edx -; X64-FAST-NEXT: imull $-294967296, %edx, %ecx # imm = 0xEE6B2800 -; X64-FAST-NEXT: subl %ecx, %edi -; X64-FAST-NEXT: movl %edi, %edx -; X64-FAST-NEXT: retq -; -; X64-SLOW-LABEL: PR38622_signed: -; X64-SLOW: # %bb.0: -; X64-SLOW-NEXT: movl $4000000000, %ecx # imm = 0xEE6B2800 -; X64-SLOW-NEXT: movq %rdi, %rax -; X64-SLOW-NEXT: shrq $32, %rax -; X64-SLOW-NEXT: je .LBB15_1 -; X64-SLOW-NEXT: # %bb.2: -; X64-SLOW-NEXT: movq %rdi, %rax -; X64-SLOW-NEXT: cqto -; X64-SLOW-NEXT: idivq %rcx -; X64-SLOW-NEXT: # kill: def $edx killed $edx killed $rdx -; X64-SLOW-NEXT: retq -; X64-SLOW-NEXT: .LBB15_1: -; X64-SLOW-NEXT: xorl %edx, %edx -; X64-SLOW-NEXT: movl %edi, %eax -; X64-SLOW-NEXT: divl %ecx -; X64-SLOW-NEXT: # kill: def $edx killed $edx def $rdx -; X64-SLOW-NEXT: # kill: def $eax killed $eax def $rax -; X64-SLOW-NEXT: # kill: def $edx killed $edx killed $rdx -; X64-SLOW-NEXT: retq +; X64-LABEL: PR38622_signed: +; X64: # %bb.0: +; X64-NEXT: movabsq $1237940039285380275, %rcx # imm = 0x112E0BE826D694B3 +; X64-NEXT: movq %rdi, %rax +; X64-NEXT: imulq %rcx +; X64-NEXT: movq %rdx, %rcx +; X64-NEXT: shrq $63, %rcx +; X64-NEXT: sarq $28, %rdx +; X64-NEXT: leaq (%rdx,%rcx), %rax +; X64-NEXT: addl %ecx, %edx +; X64-NEXT: imull $-294967296, %edx, %ecx # imm = 0xEE6B2800 +; X64-NEXT: subl %ecx, %edi +; X64-NEXT: movl %edi, %edx +; X64-NEXT: retq %2 = sdiv i64 %0, 4000000000 %3 = srem i64 %0, 4000000000 %4 = trunc i64 %3 to i32 |
