diff options
Diffstat (limited to 'llvm')
| -rw-r--r-- | llvm/test/CodeGen/X86/clz.ll | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/llvm/test/CodeGen/X86/clz.ll b/llvm/test/CodeGen/X86/clz.ll index d76741c31d1..cd8f4ca52f2 100644 --- a/llvm/test/CodeGen/X86/clz.ll +++ b/llvm/test/CodeGen/X86/clz.ll @@ -863,3 +863,124 @@ define i8 @ctlz_i8_knownbits(i8 %x) { %tmp2 = and i8 %tmp, 1 ret i8 %tmp2 } + +; Make sure we can detect that the input is non-zero and avoid cmov after BSR +; This is relevant for 32-bit mode without lzcnt +define i64 @ctlz_i64_zero_test_knownneverzero(i64 %n) { +; X32-LABEL: ctlz_i64_zero_test_knownneverzero: +; X32: # %bb.0: +; X32-NEXT: movl {{[0-9]+}}(%esp), %eax +; X32-NEXT: testl %eax, %eax +; X32-NEXT: jne .LBB21_1 +; X32-NEXT: # %bb.2: +; X32-NEXT: movl {{[0-9]+}}(%esp), %eax +; X32-NEXT: orl $1, %eax +; X32-NEXT: bsrl %eax, %eax +; X32-NEXT: xorl $31, %eax +; X32-NEXT: orl $32, %eax +; X32-NEXT: xorl %edx, %edx +; X32-NEXT: retl +; X32-NEXT: .LBB21_1: +; X32-NEXT: bsrl %eax, %eax +; X32-NEXT: xorl $31, %eax +; X32-NEXT: xorl %edx, %edx +; X32-NEXT: retl +; +; X64-LABEL: ctlz_i64_zero_test_knownneverzero: +; X64: # %bb.0: +; X64-NEXT: orq $1, %rdi +; X64-NEXT: je .LBB21_1 +; X64-NEXT: # %bb.2: # %cond.false +; X64-NEXT: bsrq %rdi, %rax +; X64-NEXT: xorq $63, %rax +; X64-NEXT: retq +; X64-NEXT: .LBB21_1: +; X64-NEXT: movl $64, %eax +; X64-NEXT: retq +; +; X32-CLZ-LABEL: ctlz_i64_zero_test_knownneverzero: +; X32-CLZ: # %bb.0: +; X32-CLZ-NEXT: movl {{[0-9]+}}(%esp), %eax +; X32-CLZ-NEXT: testl %eax, %eax +; X32-CLZ-NEXT: jne .LBB21_1 +; X32-CLZ-NEXT: # %bb.2: +; X32-CLZ-NEXT: movl {{[0-9]+}}(%esp), %eax +; X32-CLZ-NEXT: orl $1, %eax +; X32-CLZ-NEXT: lzcntl %eax, %eax +; X32-CLZ-NEXT: orl $32, %eax +; X32-CLZ-NEXT: xorl %edx, %edx +; X32-CLZ-NEXT: retl +; X32-CLZ-NEXT: .LBB21_1: +; X32-CLZ-NEXT: lzcntl %eax, %eax +; X32-CLZ-NEXT: xorl %edx, %edx +; X32-CLZ-NEXT: retl +; +; X64-CLZ-LABEL: ctlz_i64_zero_test_knownneverzero: +; X64-CLZ: # %bb.0: +; X64-CLZ-NEXT: orq $1, %rdi +; X64-CLZ-NEXT: lzcntq %rdi, %rax +; X64-CLZ-NEXT: retq + %o = or i64 %n, 1 + %tmp1 = call i64 @llvm.ctlz.i64(i64 %o, i1 false) + ret i64 %tmp1 +} + +; Make sure we can detect that the input is non-zero and avoid cmov after BSF +; This is relevant for 32-bit mode without tzcnt +define i64 @cttz_i64_zero_test_knownneverzero(i64 %n) { +; X32-LABEL: cttz_i64_zero_test_knownneverzero: +; X32: # %bb.0: +; X32-NEXT: movl {{[0-9]+}}(%esp), %eax +; X32-NEXT: testl %eax, %eax +; X32-NEXT: jne .LBB22_1 +; X32-NEXT: # %bb.2: +; X32-NEXT: movl $-2147483648, %eax # imm = 0x80000000 +; X32-NEXT: orl {{[0-9]+}}(%esp), %eax +; X32-NEXT: bsfl %eax, %eax +; X32-NEXT: orl $32, %eax +; X32-NEXT: xorl %edx, %edx +; X32-NEXT: retl +; X32-NEXT: .LBB22_1: +; X32-NEXT: bsfl %eax, %eax +; X32-NEXT: xorl %edx, %edx +; X32-NEXT: retl +; +; X64-LABEL: cttz_i64_zero_test_knownneverzero: +; X64: # %bb.0: +; X64-NEXT: movabsq $-9223372036854775808, %rax # imm = 0x8000000000000000 +; X64-NEXT: orq %rdi, %rax +; X64-NEXT: je .LBB22_1 +; X64-NEXT: # %bb.2: # %cond.false +; X64-NEXT: bsfq %rax, %rax +; X64-NEXT: retq +; X64-NEXT: .LBB22_1: +; X64-NEXT: movl $64, %eax +; X64-NEXT: retq +; +; X32-CLZ-LABEL: cttz_i64_zero_test_knownneverzero: +; X32-CLZ: # %bb.0: +; X32-CLZ-NEXT: movl {{[0-9]+}}(%esp), %eax +; X32-CLZ-NEXT: testl %eax, %eax +; X32-CLZ-NEXT: jne .LBB22_1 +; X32-CLZ-NEXT: # %bb.2: +; X32-CLZ-NEXT: movl $-2147483648, %eax # imm = 0x80000000 +; X32-CLZ-NEXT: orl {{[0-9]+}}(%esp), %eax +; X32-CLZ-NEXT: tzcntl %eax, %eax +; X32-CLZ-NEXT: orl $32, %eax +; X32-CLZ-NEXT: xorl %edx, %edx +; X32-CLZ-NEXT: retl +; X32-CLZ-NEXT: .LBB22_1: +; X32-CLZ-NEXT: tzcntl %eax, %eax +; X32-CLZ-NEXT: xorl %edx, %edx +; X32-CLZ-NEXT: retl +; +; X64-CLZ-LABEL: cttz_i64_zero_test_knownneverzero: +; X64-CLZ: # %bb.0: +; X64-CLZ-NEXT: movabsq $-9223372036854775808, %rax # imm = 0x8000000000000000 +; X64-CLZ-NEXT: orq %rdi, %rax +; X64-CLZ-NEXT: tzcntq %rax, %rax +; X64-CLZ-NEXT: retq + %o = or i64 %n, -9223372036854775808 ; 0x8000000000000000 + %tmp1 = call i64 @llvm.cttz.i64(i64 %o, i1 false) + ret i64 %tmp1 +} |
