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llvm-project/llvm/test/CodeGen/X86/fltused_math.ll

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Fix emission of _fltused for MSVC. It should be emitted when any floating-point operations (including calls) are present in the object, not just when calls to printf/scanf with floating point args are made. The difference caused by this is very subtle: in static (/MT) builds, on x86-32, in a program that uses floating point but doesn't print it, the default x87 rounding mode may not be set properly upon initialization. This commit also removes the walk of the types pointed to by pointer arguments in calls. (To assist in opaque pointer types migration -- eventually the pointee type won't be available.) That latter implies that it will no longer consider a call like `scanf("%f", &floatvar)` as sufficient to emit _fltused on its own. And without _fltused, `scanf("%f")` will abort with error R6002. This new behavior is unlikely to bite anyone in practice (you'd have to read a float, and do nothing with it!), and also, is consistent with MSVC. Differential Revision: https://reviews.llvm.org/D56548 llvm-svn: 352076
2019-01-25 02:34:00 +08:00
; The purpose of this test to verify that the fltused symbol is
; emitted when floating point operations are used on Windows.
; RUN: llc < %s -mtriple i686-pc-win32 | FileCheck %s --check-prefix WIN32
; RUN: llc < %s -mtriple x86_64-pc-win32 | FileCheck %s --check-prefix WIN64
; RUN: llc < %s -O0 -mtriple i686-pc-win32 | FileCheck %s --check-prefix WIN32
; RUN: llc < %s -O0 -mtriple x86_64-pc-win32 | FileCheck %s --check-prefix WIN64
define i32 @foo(i32 %a) nounwind {
entry:
%da = sitofp i32 %a to double
%div = fdiv double %da, 3.100000e+00
%res = fptosi double %div to i32
ret i32 %res
}
; WIN32: .globl __fltused
; WIN64: .globl _fltused